"Often refers to cellulose acetate, a semi-synthetic polymer used in photographic and cinema film. It is also the name of a salt or ester derived from acetic (ethanoic) acid. (See also Science II Database of Materials.)"
*"acetone"
AC20s
"A member of the ketone group of organic compounds, otherwise known as propanone. It contains a ketone group (C=O) attached to the central carbon. (See also Science II Database of Materials.)"
*"Aztec"
AZ10s
"A member of a Mexican Indian tribe, based in central Mexico before the sixteenth century, that established a great empire."
*"Aztecs"
AZ20s
"A Mexican Indian tribe, based in central Mexico before the sixteenth century, that established a great empire."
*"acetic acid"
AC40s
"A clear viscous liquid, otherwise known as ethanoic acid. It is a member of the carboxylic acid group of organic compounds."
*"acetylene"
AC50s
"A colourless gas otherwise known as ethyne. It is the first member in the group of organic molecules called the alkynes."
*"acid rain"
AC60s
"Acid rain is caused by carbon dioxide, sulphur dioxide, nitrogen dioxide and other pollutant {\strike gases} in the atmosphere dissolving in rain water. The {\strike gases} dissolved in water form an acidic solution causing pollution of waterways and other natural areas."
*"acid"
AC30s
"A substance which releases hydrogen ions when added to water."
*"addition reaction"
AD10s
"A chemical reaction where one molecule adds on to another. These reactions occur with unsaturated organic compounds that contain double or triple bonds."
*"adsorb"
AD20s
"The process by which one substance (usually a liquid or a gas) is attached to the surface of another substance (usually a solid)."
*"adsorbents"
AD30s
"Substances onto which other substances can attach. Often a gas or liquid is adsorbed onto the surface of a solid."
*"aggregate"
AG10s
"A substance not in solution or a material composed of a mixture of small particles which clump together."
*"agitator"
AG20s
"An instrument which is used to shake or stir a liquid substance."
*"agronomists"
AG30s
"People who study the science of land cultivation, crop production and soil management."
*"air"
AI10s
"Air is the mixture of {\strike gases} which forms the earth's atmosphere. The average composition is as follows: Nitrogen 78.08 %; oxygen 20.94 %; argon 0.934 %; carbon dioxide 0.03 %. There are traces of other {\strike gases}. Air is essential to life."
*"alkali"
AL20s
"A base which is soluble in water. Alkalis react with acids to form salt and water only."
*"alkaloid"
AL70s
"A member of a group of organic compounds, containing nitrogen, that are derived from plants and used in medicine."
*"alkane"
AL80s
"The simplest organic compounds containing hydrogen and carbon only. The atoms in alkanes are all joined together by single covalent bonds."
*"alkene"
AL90s
"Organic molecules containing hydrogen and carbon only. Two or more carbon atoms in alkene molecules are joined together by double covalent bonds."
*"alkylation"
AL100s
"The addition of an alkyl group to a compound. An alkyl group is obtained by removing a hydrogen atom from an alkane."
*"alkynes"
AL110s
"Organic molecules containing carbon and hydrogen only. Two or more atoms in alkyne molecules are joined together by triple covalent bonds."
*"allotrope"
AL30s
"Allotropes are elements which exist in two or more different forms in the same physical state. The chemical properties of each allotrope are the same, but the physical properties are different. Carbon, for example, has two allotropes, sulphur has five."
*"alloy"
AL40s
"An alloy is a mixture of two or more metals, or a mixture of metals and non-metals. By joining together two or more elements particular properties can be obtained."
*"alloys"
AL50s
"An {\strike alloy} is a mixture of two or more metals, or a mixture of metals and non-metals. By joining together two or more elements particular properties can be obtained."
*"alluvial"
AL120s
"A type of fertile soil, containing mud, silt and sand, that has been deposited by rivers or streams."
*"alpacas"
AL130s
"Domesticated mammalian animals that come from South America and are related to the llama."
*"amalgam"
AM10s
"An amalgam is an alloy containing mercury."
*"amide group"
AM40s
"A molecular side group containing a nitrogen atom attached to two hydrogen atoms. The nitrogen is able to form three covalent bonds and so the amide group is found attached to carbon atoms in various organic molecules, such as amino acids."
*"amino acids"
AM50s
"A group of organic molecules which consist of a carboxylic acid containing an amino group. The simplest amino acid is amino methanoic acid. Amino acids are used as the building blocks for making proteins."
*"amino glycosides"
AM60s
"An organic compound, derived from a sugar (saccharide), that contains an amino group."
*"ammonia"
AM70s
"A pungent gas with the formula NH{\dn6 3}."
*"ammonification"
AM80s
"The process of adding ammonia to something."
*"ammonium"
AM90s
"The positive ion derived from ammonia. The ion has a single positive charge and consists of four hydrogen atoms attached to a nitrogen atom."
*"amorphous"
AM100s
"Amorphous materials are non-crystalline, meaning they have no definite shape or form."
*"anaemia"
AN120s
"A disease in which the body does not have enough red blood cells."
*"analgesic"
AN110s
"A drug that helps relieve pain."
*"anhydrous"
AN10s
"Anhydrous substances contain no water."
*"anion"
AN20s
"A negatively charged ion. During electrolysis, anions are attracted to the anode."
*"annealed"
AN30s
"Annealing is the toughening of a metal. It involves the metal being heated then slowly cooled."
*"annealing"
AN40s
"Annealing is the toughening of a metal. It involves the metal being heated then slowly cooled."
*"anode"
AN50s
"A positive electrode. Negatively charged ions - called anions - flow to the anode during electrolysis."
*"anti caking agent"
AN140s
"A substance added to another that stops the particles in it clumping together."
*"antibiotic"
AN60s
"A substance produced by a micro-organism (for example a bacterium) which is able to kill or inhibit the growth of another micro-organism. (See also Science II Database of Materials.)"
*"antigen"
AN150s
"A chemical, often a toxin, produced by the cells in one organism that stimulates the production of antibodies in another organism."
*"antiknock"
AN80s
"Antiknock agents are added to engine fuel to prevent knocking, a shuddering sound in engines caused by the uneven burning of fuel."
*"antiknocking"
AN90s
"{\strike Antiknock} agents are added to engine fuel to prevent knocking, a shuddering sound in engines caused by the uneven burning of fuel."
*"antimony"
AN160s
"A toxic metallic element, symbol Sb, that belongs to group V of the periodic table."
*"antiseptic"
AN100s
"Antiseptics are substances used to kill or prevent the growth of micro-organisms. (See also Science II database of Materials.)"
*"aqua regia"
AQ10s
"Aqua regia is a mixture of concentrated hydrochloric acid and concentrated nitric acid. It dissolves very unreactive metals such as gold."
*"aragonite"
AR20s
"A mineral rock found in nature that consists of anhydrous calcium carbonate."
*"aromatics"
AR30s
"An aromatic compound that contains a benzene ring (a ring of six carbon atoms joined by alternating double and single bonds)."
*"arsenic"
AR40s
"A toxic metalloid element, symbol As, that belongs to group V of the periodic table."
*"arthritis"
AR10s
"Arthritis is a condition in which there is an inflammation of joints. It causes pain, swelling and restriction of movement."
*"aseptic"
AS40s
"A germ free environment/area."
*"atmospheric fixation"
AT50s
"The incorporation of {\strike gases} in the atmosphere into compounds that can be used by living organisms. The process is often carried out by bacteria in the soil."
*"atmospheric"
AT40s
"Relating to the earth's atmosphere."
*"atom"
AT20s
"An atom is the smallest part of an element that can exist which is recognisably part of a particular element. It consists of a unique configuration of protons, neutrons and electrons and can always be identified as belonging to a specific element."
*"atomic number"
AT30s
"The atomic number (also known as the proton number) is equal to the number of protons to be found in the nucleus of an atom. Every element has a unique proton number and each atom of that element has the same number of protons."
*"Bakelite"
BA10s
"The first synthetic plastic to be manufactured, made from phenol and formaldehyde. It is relatively brittle but useful as an electrical insulator. (See also Science II Database of Materials.)"
*"Babylonia"
BA80s
"The Empire of Mesopotamia, founded in the eighteenth century BCE and was centred around the city of Babylon."
*"Babylonians"
BA90s
"People who came from the great Empire of Babylonia/Mesopotamia which was founded in the eighteenth century BCE."
*"Bayer process"
BA140s
"The first stage during the extraction of aluminium from its ore, in which alumina (aluminium oxide) is separated from bauxite ore."
*"Byzantine"
BY10s
"Relating to the Empire established by Constantine in 330 BCE. This Empire was a continuation of the Roman Empire, in the Middle East."
*"bacteria"
BA100s
"Microscopic one-celled organisms. Many are useful in nature although some bacteria do cause disease."
*"barrel"
BA110s
"A unit of measurement often used for crude oil. One barrel equals 35 UK gallons. This is approximately equivalent to 159 litres."
*"base"
BA50s
"A substance which reacts with an acid to form a salt and water only.
Also refers to the bottom of something."
*"batholith"
BA120s
"A large mass of igneous rock found at the earth's surface that has an exposed surface of over 104 sq km."
*"batholiths"
BA130s
"Large masses of igneous rock that have exposed surfaces of over 104 sq km."
*"battery"
BA60s
"Batteries convert chemical energy into electrical energy. They provide a portable source of power."
*"benefication"
BE10s
"The separation of a mineral ore into its components and removal of the waste as slag."
*"benzene"
BE20s
"A colourless organic liquid containing hydrogen and carbon. It has six carbon atoms joined in a ring by alternating single and double covalent bonds, with one hydrogen atom joined to each of the carbon atoms."
*"billion"
BI40s
"In the U.K. a billion is one million million. (In the U.S. a billion represents one thousand million.)"
*"biodegradable"
BI20s
"A material which can be decomposed by bacteria, fungi or other organisms."
*"biological fixation"
BI50s
"The process of incorporating certain {\strike gases} from the air into the components of compounds. The process is mainly carried out by micro-organisms in the soil."
*"bismuth"
BI60s
"Pinkish white metallic element belonging to group V of the periodic table, symbol Bi."
*"boil"
BO10s
"To change a liquid to a gas by heating."
*"boiling point"
BO20s
"The boiling point of a liquid is the temperature at which the liquid changes to a gas."
*"bonds"
BO30s
"Bonds are the links joining atoms in molecules and giant structures."
*"brecciated"
BR60s
"Substance, such as a rock, which is made up of many small angularly shaped constituents."
*"brine"
BR70s
"A solution of salt (sodium chloride) in water."
*"brittle"
BR40s
"Brittle solids break into pieces under force."
*"bronze"
BR50s
"Bronze is an alloy of copper (about 90%) and tin (10%). The tin strengthens and hardens the copper."
*"bubble cap"
BU30s
"Found in fractional distillation columns used for purifying crude oil. Several caps are positioned over gaps in the metal trays used to collect each distillation fraction. They help the fraction condense at the required level."
*"caffeine"
CA10s
"A naturally occurring drug found in tea and coffee that acts as a stimulant and diuretic. It has the formula C{\dn6 8}H{\dn6 10}N{\dn6 4}O{\dn6 2}."
*"chromium"
CH70s
"A blue-white metal belonging to the transition series of elements, symbol Cr. It has the common oxidation states of +2, +3 and +6 in its compounds."
*"Cambrian"
CA180s
"The first 100 million years of the Palaeozoic era, approximately 500 million years ago."
*"Confederation of Independent States"
CO30s
"The States of Northern Asia and Eastern Europe which were formerly the USSR."
*"calcining"
CA160s
"The treatment of a substance so that it is oxidised, reduced or loses water."
*"calcium"
CA170s
"Metallic element belonging to group II of the periodic table, symbol Ca."
*"carbonaceous"
CA190s
"A substance which contains carbon."
*"carbonate"
CA200s
"A compound which contains the negative carbonate ion, CO{\dn6 3}{\up6 2-}."
*"carbonisation"
CA210s
"The process of changing an organic compound into carbon by heat."
*"carboxyl group"
CA220s
"The negative organic ion -COOH{\up6 -}."
*"carboxylic acid"
CA230s
"An organic acid that contains C attached by a double bond to O, by a single bond to the hydroxyl ion OH{\up6 -} and by a single bond to the rest of the molecule."
*"cartilage"
CA240s
"Tough elastic tissue attaching one bone to another. It helps in the movement of joints."
*"catalysis"
CA110s
"Catalysis is the use of a catalyst to hasten the rate of a chemical reaction."
*"catalyst"
CA120s
"A catalyst is a substance that speeds up a chemical reaction. During catalysis the catalyst itself does not undergo any lasting chemical change."
*"catalytic converter"
CA250s
"A device found in motor vehicles which removes poisonous {\strike gases}, e.g. sulphur dioxide and nitrogen dioxide, from car exhaust fumes."
*"cathode"
CA130s
"A negative electrode. Positively charged ions - called cations - flow to the cathode during electrolysis."
*"cation"
CA140s
"A positively charged ion. During electrolysis, cations are attracted to the cathode."
*"caulk"
CA260s
"To block up cracks or seams with a filler material."
*"caustic soda"
CA270s
"A common name for the white solid, sodium hydroxide."
*"caustic"
CA150s
"Caustic materials burn and corrode organic materials, including flesh."
*"cetane number"
CE30s
"A measure of how well a diesel fuel will ignite in a diesel engine."
*"chain"
CH80s
"A line of atoms or molecules of the same type in an compound."
*"chains"
CH90s
"Atoms or molecules of the same type all joined together to form a long compound."
*"chassis"
CH100s
"The steel frame, wheels and mechanical parts of a motor vehicle."
*"chipboard"
CH110s
"A rigid sheet containing particles of wood compressed together."
*"chloramphenicol"
CH120s
"A type of antiseptic, often used to treat typhoid and rickets."
*"chlorophyll"
CH130s
"The green component of plant cells, vital in the process of photosynthesis which makes food for the plant."
*"cholesterol"
CH140s
"A white/yellow waxy insoluble organic compound called a sterol. It is found in all animal tissues, blood and bile."
*"cinchona"
CI30s
"A tree or shrub native to South America. Quinine can be obtained from the bark of the tree and is used in medicine."
*"circuit"
CI10s
"An electrical circuit is an apparatus through which an electrical current flows."
*"citrus fruits"
CI40s
"Fruits obtained from tropical or subtropical Citrus trees. The fruits have hard skins and soft fleshy centres which contain the seeds."
*"cleavable"
CL20s
"A substance which can be broken up into smaller parts."
*"cleavage"
CL30s
"The splitting or breaking up of a substance into smaller parts."
*"climate"
CL40s
"The weather conditions which occur in a particular area."
*"coagulate"
CO290s
"The process in which small particles or particles in solution clump together to form a solid mass."
*"coagulating"
CO300s
"The clumping together of small particles or particles in solution."
*"coal tar"
CO310s
"A black sticky substance formed by burning coal in a limited amount of air."
*"coke"
CO320s
"A black solid, mostly containing carbon, produced by burning coal at very high temperatures."
*"combustion"
CO50s
"Combustion is the name given to a chemical reaction in which a substance combines with a gas to give heat and light. It commonly involves reaction with oxygen."
*"compound"
CO60s
"A substance in which two or more elements are joined by a chemical bond. It is possible to decompose a compound into simpler substances. Compounds have fixed chemical compositions, and can be described by a formula."
*"condensation reaction"
CO330s
"A chemical reaction where two molecules join together forming a larger molecule and releasing a small molecule, such as water."
*"condense"
CO90s
"A substance is said to condense when the vapour cools and becomes a liquid."
*"condensed"
CO100s
"A substance is said to have condensed when the vapour has cooled and become a liquid."
*"condenses"
CO110s
"Condensation is the change that occurs when a vapour cools and becomes a liquid."
*"condensing"
CO120s
"Condensation is the change that occurs when a vapour cools and becomes a liquid."
*"conductive"
CO130s
"Conductors are substances which allow heat or electricity to flow through them. Substances which do not allow this are called insulators."
*"conductivity"
CO140s
"Conductors are substances which allow heat or electricity to flow through them. Substances which do not allow this are called insulators."
*"conductor"
CO150s
"A conductor is a substance which allows heat or electricity to flow through it. A substance which does not allow this is called an insulator."
*"coniferous"
CO350s
"Trees and shrubs which keep their leaves on all year round. They often bear shiny leaves and cones."
*"continental crust"
CO360s
"The rock masses making up the different continents of the earth which, according to the theory of continental drift, move gradually over the planet's surface."
*"copolymer"
CO370s
"A polymer made from two or more different molecules as starting units."
*"copolymerisation"
CO170s
"The joining together of two or more different molecules to form a polymer."
*"corrode"
CO230s
"{\strike Corrosion} is a process whereby the surface of a solid is chemically attacked. This often involves a metal reacting with an atmospheric gas. The reaction of iron with oxygen to form rust is well known."
*"corroded"
CO240s
"{\strike Corrosion} is a process whereby the surface of a solid is chemically attacked. This often involves a metal reacting with an atmospheric gas. The reaction of iron with oxygen to form rust is well known."
*"corrosion"
CO250s
"Corrosion is a process whereby the surface of a solid is chemically attacked. This often involves a metal reacting with an atmospheric gas. The reaction of iron with oxygen to form rust is well known."
*"corrosive"
CO260s
"Corrosive substances cause corrosion."
*"covalent"
CO280s
"Covalent bonds are formed when 2 atoms join by sharing electrons. Hydrogen molecules contain two atoms joined covalently."
*"cracking"
CR10s
"Cracking is the process used in the refining of petroleum, by which hydrocarbon molecules are broken down into smaller molecules. These molecules are then used in the production of chemicals and fuels."
*"cryolite"
CR30s
"A white solid fluoride of sodium or aluminium. It is used in the manufacture of aluminium, glass and enamel."
*"crystalline"
CR20s
"Crystalline materials have a regular internal arrangement of atoms, ions or molecules, though they need not necessarily exist as crystals."
*"curd"
CU10s
"The solid part obtained by leaving milk to sour."
*"dairy product"
DA10s
"A food substance obtained from milk."
*"deciduous"
DE90s
"Trees or shrubs which do not stay green all year round. The leaves of the plants are shed at the end of the growing season each year."
*"decompose"
DE10s
"{\strike Decomposition} is a chemical reaction in which a compound breaks down into simpler compounds or into elements."
*"decomposes"
DE20s
"{\strike Decomposition} is a chemical reaction in which a compound breaks down into simpler compounds or into elements."
*"decomposition"
DE30s
"Decomposition is a chemical reaction in which a compound breaks down into simpler compounds or into elements."
*"dehydrogenation"
DE100s
"The removal of hydrogen from a substance."
*"deliquescence"
DE40s
"Deliquescence is the absorption of water from the atmosphere by a substance to such an extent that a solution is formed. Substances that deliquesce are said to be deliquescent."
*"deliquescent"
DE50s
"Deliquescence is the absorption of water from the atmosphere by a substance to such an extent that a solution is formed. Substances that deliquesce are said to be deliquescent."
*"denitrification"
DE110s
"The removal of nitrogen from a substance."
*"dense"
DE120s
"A thick material which has its constituent atoms or molecules closely packed."
*"density"
DE70s
"The density of a substance is the mass of one cubic metre of the substance. It may be calculated by dividing mass by volume."
*"dentin"
DE130s
"Dentin or dentine is a protein and calcium-containing tissue and is the main constituent of mammalian teeth."
*"deoxidised"
DE140s
"A substance which has had oxygen atoms removed from it."
*"desulphurisation"
DE160s
"The removal of sulphur from a substance, often from the products of crude oil distillation."
*"dewaxing"
DE150s
"The removal of waxy compounds from a substance."
*"diabetics"
DI100s
"A person who suffers from diabetes, a disease in which the body has an excess amount of sugars in the blood and urine."
*"diet"
DI110s
"The types and quantities of food consumed by a person."
*"dietary"
DI120s
"Concerning matters related to types and quantities of food consumed by a person."
*"digestion"
DI130s
"The breaking down of food into its components so that they can be used by the body."
*"digestive system"
DI140s
"The organs of the body which allow the ingestion and digestion of food and the excretion of waste from the body."
*"dilutant"
DI150s
"A liquid, often water, used to make a solution or a liquid less concentrated or thinner."
*"dilute"
DI160s
"To thin down a liquid or solution or make it less concentrated."
*"diluting"
DI170s
"To thin down a liquid or solution or make it less concentrated."
*"discharge tube"
DI40s
"A discharge tube is a gas filled tube with an electrode at each end. Passing an electric current through the gas produces light. Fluorescent tubes are discharge tubes."
*"disinfectant"
DI50s
"A disinfectant is a substance which kills bacteria."
*"dissolve"
DI70s
"Substances are said to dissolve when they are mixed in a liquid and form a solution."
*"distillation"
DI80s
"A liquid is said to have been distilled when it has been heated to a vapour and then condensed back to a liquid. Distillation is used to purify and separate liquids."
*"dolomite"
DO10s
"A mineral rock containing calcium and magnesium carbonate."
*"dorΘ"
DO20s
"A mixture of gold and silver in bars or mass form ready for further processing."
*"double bond"
DO30s
"A covalent bond where the two atoms making the bond share two pairs of electrons. In a single bond between two atoms one pair of electrons is shared making the bond."
*"ductile"
DU10s
"A ductile substance can be easily drawn into wires."
*"ductility"
DU20s
"The ability to be easily drawn into thin wires."
*"durability"
DU30s
"Long lasting and enduring."
*"Edict of Nantes"
ED10s
"A law given by Henry IV at the end of the Wars of Religion (1562-1598) granting the Huguenot's religious and civil rites. Louis XIV later revoked the edict."
*"elastic"
EL10s
"The ability of a solid to regain its original shape after deformation. If a material exceeds its elastic limit on deformation, then it is unable to return to its original shape."
*"electrode"
EL20s
"An electrode is a conductor which allows an electric current to pass through an {\strike electrolyte}. The current enters and leaves the {\strike electrolyte} solution through the electrodes."
*"electrolytic"
EL30s
"A process where electrolysis is used. Elements are extracted from solution or molten substance (the electrolyte), where they are found in their ionic form, by the use of electricity."
*"electrolysis"
EL40s
"A process in which an electrical current is passed through an electrolyte producing chemical changes at each electrode. The electrolyte decomposes. Elements can be extracted from their compounds in this way."
*"electrolyte"
EL50s
"An electrolyte is a compound that, when molten or in solution, will conduct an electric current. The current decomposes the electrolyte."
*"electrolytical"
EL110s
"A process where electrolysis is used. Elements are extracted from solution or molten substance (the electrolyte), where they are found in their ionic form, by the use of electricity."
*"electromagnetic"
EL60s
"Electromagnetic radiation is a form of energy that travels in waves."
*"electron"
EL70s
"An electron is an extremely small, negatively charged particle that moves around the nucleus of an atom. The number of {\strike electrons} is always equal to the number of positively charged protons. The mass of an electron is 1840 times less than that of a proton."
*"electrons"
EL80s
"An {\strike electron} is an extremely small, negatively charged particle that moves around the nucleus of an atom. The number of electrons is always equal to the number of positively charged protons. The mass of an {\strike electron} is 1840 times less than that of a proton."
*"electroplating"
EL120s
"Electroplating is a method of coating one metal with a thin layer of another metal, either for protection or for decoration."
*"element"
EL100s
"A pure substance that cannot be broken down into simpler substances by normal chemical means. Each element has a unique atomic number. All substances and materials are composed of elements."
*"emulsion"
EM20s
"A liquid mixture in which one liquid is suspended in another as fine droplets."
*"emulsifiers"
EM30s
"A substance which stabilises an emulsion, i.e. they help hold one liquid as fine droplets dispersed within another liquid."
*"endothermic"
EN20s
"A chemical reaction which requires heat energy from the surroundings in order to take place."
*"enzyme"
EN40s
"A compound which catalyses reactions in living organisms."
*"epidermal"
EP10s
"Relating to the outer layer of the skin of mammals, called the epidermis."
*"ester"
ES20s
"An organic compound formed by the reaction between an alcohol and an acid with the elimination of water."
*"esterification"
ES10s
"A condensation reaction in which an acid reacts with an alcohol forming an ester."
*"ethanol"
ET10s
"An organic compound, second in the homologous series called the alcohols. The functional group is a hydroxyl group (-OH)."
*"eutrophication"
EU10s
"The nutrient run-off from agriculture, industry or home use, which pollutes rivers and streams, causing an increase in algae growth. This leads to depletion of oxygen in the water and subsequently kills off other aquatic life."
*"evergreen"
EV10s
"Trees and shrubs which keep their leaves on throughout the year, such as pine trees."
*"exothermic"
EX10s
"A chemical reaction which gives out heat energy to the surroundings."
*"extinction"
EX20s
"The complete destruction of an animal or plant species."
*"extrusion"
EX30s
"A process during the manufacture of certain materials (for example, nylon) during which the material is forced through several small holes in a block."
*"Flanders"
FL70s
"A historical region in north-west Belgium. Traditionally a region of farming and textiles, it was a scene of heavy fighting during both World Wars."
*"fatigue"
FA10s
"Tiredness or the tendency of a material to weaken or break when subjected to a repeated stress or force."
*"fermentation"
FE30s
"A chemical reaction carried out by certain micro-organisms such as yeast where sugar is converted to ethanol and carbon dioxide."
*"fertilisers"
FE40s
"Substances or combinations of substances added to the soil to provide the nutrients essential for the healthy growth of plants. Compounds containing potassium, nitrogen, sulphur and phosphorous are the common constituents of artificial fertilisers."
*"fertiliser"
FE20s
"A substance or combination of substances added to soil to provide the nutrients essential to the healthy growth of plants. Compounds containing potassium, nitrogen, sulphur and phosphorus are the common constituents of artificial {\strike fertilisers}."
*"fired"
FI20s
"The supply of heat."
*"flammability"
FL60s
"Flammable substances burst into flames easily; non-flammable substances do not."
*"flammable"
FL20s
"Flammable substances burst in to flames easily; non-flammable substances do not."
*"flax"
FL80s
"A shrubby perennial plant. Fibres are extracted from the stems and used to produce thread that is woven into cloth."
*"fluorescent"
FL40s
"Fluorescent lights consist of a gas filled tube with an electrode at each end. Passing an electrical current through the gas produces light. Fluorescence stops when the electrical excitement stops."
*"flux"
FL90s
"A flow of something. A substance added to another to lower its boiling point. A substance used to increase the fluidity of molten metal slag."
*"forged"
FO10s
"To have formed or made something in the required shape."
*"fossils"
FO20s
"The remains or imprint in certain minerals of a plant or animal that existed in a past geological time."
*"fractional distillation"
FR10s
"Fractional distillation is a process for separating liquids from a mixture by making use of their different physical properties."
*"fracture"
FR20s
"A break or crack in something. In minerals or rocks, a fracture is the way that they break naturally."
*"fungi"
FU10s
"A group of organisms, including moulds, yeasts and mushrooms. They can be unicellular or multicellular and reproduce by spore formation."
*"galvanisation"
GA10s
"Galvanisation is the process of coating iron or steel with a layer of zinc, which is both more resistant to corrosion and more reactive than the underlying metal, thus providing protection even when the zinc coating is scratched."
*"gas"
GA20s
"Gas is a state of matter in which atoms and molecules are linked by very few bonds, and are therefore given a greater freedom of movement. {\strike Gases} have a fixed mass but no fixed volume or shape."
*"gasoline"
GA40s
"The name used in the US for petrol. A hydrocarbon fraction produced by the fractional distillation of crude oil."
*"genus"
GE10s
"A group of organisms containing several related species."
*"geology"
GE20s
"The study of the age, structure and composition of the minerals and rocks in the earth."
*"global warming"
GL30s
"The result of an increase in carbon dioxide and other greenhouse {\strike gases} which can absorb heat. These {\strike gases} cause increasing amounts of heat to be trapped in the earth's atmosphere producing an increase in temperatures world-wide."
*"glucose"
GL40s
"A white crystalline solid. One of the simplest sugars (saccharides) called a monosaccharide. It is an organic compound with the formula C{\dn6 6}H{\dn6 12}O{\dn6 6}."
*"granular"
GR40s
"A substance containing small grains or particles."
*"granules"
GR50s
"The small grains or particles of a substance."
*"greenhouse effect"
GR60s
"The process that occurs in the earth's atmosphere where the presence of carbon dioxide and other {\strike gases} cause heat to be trapped in the atmosphere."
*"greenhouse gases"
GR70s
"The {\strike gases} present in the earth's atmosphere which can absorb heat therefore causing the greenhouse effect and global warming. These {\strike gases} include carbon dioxide, sulphur dioxide and nitrogen dioxide."
*"Hall-Heroult"
HA50s
"A large cell used in industry to extract aluminium from its ore by electrolysis."
*"Huguenot"
HU20s
"A group of French Protestants whose rivalry with opposing Catholic Houses in the Middle Ages started off the Wars of Religion (1562-98). They were later persecuted under Louis XIV."
*"Haber process"
HA10s
"The Haber process is the process of making ammonia from hydrogen and nitrogen."
*"haemoglobin"
HA30s
"Haemoglobin is the substance found in red blood cells which carries oxygen around the body."
*"haemophilia"
HA40s
"An inheritable disease affecting men where the blood lacks the ability to clot when wounding occurs."
*"heliographs"
HE20s
"A device which sends messages using flashes of light."
*"homogenises"
HO50s
"The breaking up of a substance so that its particles are all of identical sizes."
*"homogenous"
HO10s
"A substance or substances having the same kind of form or structure throughout."
*"horizons"
HO60s
"The different layers in a substance, such as the separate horizons in soil."
*"hormone"
HO70s
"A hormone is a chemical secreted from one part of the body which passes into the blood stream and then has an effect on another part of the body. It carries specific messages to certain cells and tissues."
*"hormones"
HO40s
"Hormones are chemicals secreted from one part of the body which pass into the blood stream and then have an effect on another part of the body. They carry specific messages to certain cells and tissues."
*"humidity"
HU30s
"The dampness, that is the presence of water vapour in the local atmosphere."
*"hydrate"
HY10s
"A hydrate is a compound which has water chemically combined with it."
*"hydrated"
HY70s
"The presence of water in a substance."
*"hydraulic"
HY80s
"Something operated by the use of liquids in motion or under pressure."
*"hydrocarbon"
HY90s
"An organic compound containing carbon and hydrogen."
*"hydrocracking"
HY100s
"The process of splitting large hydrocarbons into smaller molecules."
*"hydrofluoric acid"
HY110s
"An inorganic compound made by dissolving the liquid hydrogen fluoride, HF in water."
*"hydrogen bonding"
HY30s
"Intermolecular bonds between one molecule having a hydrogen atom carrying a slightly positive charge and an atom (often oxygen, nitrogen or fluorine) on another molecule carrying a slightly negative charge."
*"hydrogenation"
HY20s
"Hydrogenation, also known as hardening, involves the conversion of an unsaturated compound into a saturated compound by the addition of hydrogen."
*"hydrophilic"
HY40s
"A molecule which is attracted to water (a water-loving molecule)."
*"hydrophobic"
HY50s
"A molecule that does not like water and does not have a liking for it (a water-hating molecule)."
*"hydrous"
HY120s
"A substance containing water."
*"hydroxyl group"
HY130s
"A chemical group derived from water. It has the formula -OH, and is the active group in alcohols and other organic compounds."
*"hygroscopic"
HY60s
"A substance which absorbs water from the air."
*"Incas"
IN90s
"One of the world's major civilisations in the fifteenth century. An estimated population of 5-10 million Indians centred in the Andean Highlands of South America."
*"Industrial Revolution"
IN110s
"The transformation that occurred in Britain and other countries during the eighteenth and nineteenth centuries from a mainly agricultural culture to a mainly manufacturing, industrial culture."
*"igneous"
IG10s
"Igneous rocks are formed by the cooling of magma."
*"ignite"
IG20s
"To ignite a substance is to make it burn."
*"ignites"
IG20s
"To {\strike ignite} a substance is to make it burn."
*"ignition"
IG40s
"To ignite a substance is to make it burn."
*"impervious"
IM10s
"A substance through which water cannot pass."
*"industrial fixation"
IN100s
"The application of industrially produced compounds, such as fertilisers, to the soil so that they can be used by micro-organisms and plants and enrich the soil."
*"inert gases"
IN10s
"The {\strike inert}, or noble, {\strike gases} are extremely unreactive {\strike gases}. The name noble {\strike gases} is now preferred as the {\strike gases} are now known to create compounds."
*"inert"
IN20s
"Substances which are inert are unreactive."
*"inflammable"
IN120s
"A substance which can be easily set on fire or burnt."
*"inorganic"
IN40s
"Inorganic chemistry is the study of all elements other than carbon. This includes, however, carbonates, hydrogencarbonates, carbon the element, and its oxides."
*"insecticide"
IN50s
"An insecticide is a chemical used to kill insects."
*"insecticides"
IN50s
"Insecticides are chemicals used to kill insects."
*"insoluble"
IN70s
"Insoluble substances cannot be dissolved in a liquid."
*"insulator"
IN80s
"An insulator is a substance which is a poor conductor of heat or electricity."
*"internal combustion engine"
IN130s
"The engine used in cars and other motor vehicles. The power used to drive the vehicle comes from heat produced within the engine."
*"ion"
IO10s
"An ion is an atom which has lost or gained one or more electrons and acquired an electrical charge. The loss of an electron gives a positively charged ion, the gain of one gives a negatively charged ion."
*"ions"
IO20s
"An {\strike ion} is an atom which has lost or gained one or more electrons and acquired an electrical charge. The loss of an electron gives a positively charged {\strike ion}, the gain of one gives a negatively charged {\strike ion}."
*"irrigation"
IR40s
"The addition of water to cropland by man made devices such as hoses, pumps and channels."
*"isotope"
IS20s
"Isotopes are atoms of the same element with different numbers of neutrons. The number of protons in an element's atom always remain the same, but the number of neutrons can vary."
*"kiln"
KI10s
"A large oven used for the manufacturing, drying or burning of various materials."
*"lactic acid"
LA40s
"A clear syrupy liquid. It is produced by fermenting lactose, for example by the souring of milk."
*"lactose"
LA50s
"Milk sugar. The molecule is a disaccharide containing one glucose and one galactose molecule joined together. It is produced by mammalian mothers in the mammary glands to feed their young."
*"laminating"
LA60s
"The joining together or compression of a material into layers of thin sheets."
*"laterite"
LA10s
"A laterite is a mineral containing hydrated iron and aluminium oxides, hydroxides, clay minerals and some silica. It is formed by the weathering of rocks such as basalts."
*"laterisation"
LA20s
"A {\strike laterite} is a mineral containing hydrated iron and aluminium oxides, hydroxides, clay minerals and some silica. It is formed by the weathering of rocks such as basalts."
*"laxative"
LA30s
"A laxative is a drug which encourages emptying of the bowels."
*"leached"
LE30s
"To have washed away/removed something by water. In the case of soil, nutrients can often be leached from soil by the passage of water through it."
*"leavening"
LE40s
"The rising of dough or batter by carbon dioxide gas produced during the fermentation of dough by yeast or other microbes."
*"leukaemia"
LE50s
"A serious disease caused by cancer of the white blood cells in the body. The white blood cells increase in massive amounts overcrowding the bone marrow, spleen and lymph system."
*"leucocytes"
LE60s
"The white blood cells."
*"limonite"
LI80s
"A member of a group of naturally occurring hydrous iron oxide minerals."
*"liquid"
LI90s
"Liquid is a state of matter in which the bonds between particles are weaker than those in solids, but stronger than those in {\strike gases}. A liquid always takes up the shape of the vessel in which it resides, having a fixed mass and volume, but no fixed shape."
*"llamas"
LL10s
"A domesticated South American mammal related to the African camel."
*"loam"
LO10s
"A rich, fertile soil containing sand, clay and humus (decaying organic matter)."
*"loamy"
LO20s
"A soil which is rich and fertile and contains sand, clay and humus (decaying organic matter)."
*"lubricant"
LU10s
"A lubricant is a slippery substance, such as grease, which is used to ensure the smooth running of machinery. It prevents friction between moving parts."
*"lustre"
LU20s
"Shine."
*"lustrous"
LU30s
"Shiny."
*"Moh's scale"
MO50s
"A scale used to measure the hardness of a material."
*"machineability"
MA120s
"The ability of a substance to be processed and worked to a required shape."
*"magma"
MA10s
"Magma is molten rock found beneath the Earth's crust."
*"magnetite"
MA130s
"A naturally occurring mineral rock containing iron II and iron III oxide."
*"malleability"
MA60s
"The ease with which a substance can be beaten or hammered into sheets."
*"malleable"
MA70s
"Able to be beaten or hammered into sheets. Malleable materials are usually also ductile."
*"man-made"
MA140s
"A material that has been processed or manufactured by humans."
*"manganese"
MA150s
"Symbol Mn. A grey brittle metal belonging to the transition group of elements. It has the oxidation states +2, +4, +6 or +7 in its compounds."
*"mass"
MA100s
"Mass describes the amount of material in a substance. Unlike weight, it is not affected by gravity. Mass also applies to a dense aggregation of objects."
*"matter"
MA110s
"Matter is everything that has mass and takes up space."
*"melt"
ME10s
"To change a solid to a liquid by heating."
*"melting point"
ME20s
"The melting point of a solid is the point at which a solid changes to a liquid."
*"meningitis"
ME80s
"An infection which can be fatal, that causes an inflammation of the membranes surrounding the brain and spinal chord."
*"metabolism"
ME90s
"All the chemical processes which occur in living organisms."
*"metal"
ME40s
"Metal is the general term denoting those elements which are shiny, ductile and malleable, good conductors of heat and electricity, possessors of high melting and boiling points, and which tend to form positive ions during chemical reactions."
*"metalloid"
ME50s
"An element that is neither a metal nor a non-metal. It has properties that are characteristic of both groups. Metalloids such as silicon and arsenic are often used as semiconductors."
*"metamorphic"
ME100s
"Referring to rocks which have been altered from their original form by the action of heat and pressure."
*"metamorphism"
ME110s
"The alteration of a substance, often mineral rocks, from their original form by the presence of heat and pressure."
*"methanol"
ME120s
"A colourless toxic liquid. It is the simplest member of the homologous group of organic compounds called the alcohols which have the hydroxyl -OH group as their active group."
*"micas"
MI10s
"Micas are minerals with layer structures and complex chemistries. They often contain potassium, aluminium, magnesium, sodium and iron. An example is muscovite."
*"mildew"
MI60s
"A name for mould, often occurring on damp surfaces. A disease of plants caused by certain types of fungi."
*"mineral"
MI40s
"An inorganic material that occurs in nature."
*"mixture"
MI50s
"Two or more substances put together form a mixture. The substances in a mixture are not chemically combined and can be separated by physical means. Examples include air and gunpowder. Mixtures can be solids, liquids or {\strike gases}."
*"molecular weight"
MO60s
"Also the relative molecular mass of a compound. It is a ratio of the mass of one molecule of a compound compared with 1/12 mass of the C-12 isotope."
*"molecule"
MO10s
"A molecule is the smallest particle of an element or a compound that can exist independently. It is usually constituted of a group of atoms joined by covalent bonds. Examples are oxygen and water."
*"molten"
MO20s
"molten substances are substances which are solid at room temperature, but have now been heated to a liquid state."
*"molybdenum"
MO70s
"A hard silvery metal, symbol Mo. It is a member of the transition series of elements."
*"monoclinic"
MO80s
"A type of ionic crystal where the three axes of the crystal are not equal and two of the axes are not at right angles to each other."
*"monomer"
MO90s
"A molecule which joins to itself or others to form a polymer."
*"mosaic"
MO100s
"A design made of different colours. Often it is a design consisting of small pieces of a material such as glass or stone put together to give a picture."
*"Neolithic"
NE30s
"A cultural period of early man characterised by the use of primitive farming methods and simple stone tools."
*"naphtha"
NA20s
"A fraction from the distillation of crude oil containing hydrocarbons which are further split up to produce alkenes and some alkanes. These products are then used as the starting materials for most of the petrochemical and plastic industries."
*"nectar"
NE20s
"A sugary fluid containing sucrose produced in flowers to attract insects in order to spread their pollen to other plants causing fertilisation."
*"nerves"
NE40s
"The fibres connecting the brain to all parts of the body. They transmit sensations to the brain and instructions for the appropriate reactions to these sensations from the brain"
*"neutron"
NE10s
"A neutron is a particle found in the nucleus of an atom. Its mass is almost equivalent to that of a proton. It has no electric charge."
*"neutrons"
NE10s
"Neutrons are particles found in the nucleus of an atom. Their mass is almost equivalent to that of a proton. They have no electric charge."
*"neutropenia"
NE50s
"A low white blood cell count in the body."
*"nicotine"
NI60s
"Colourless, poisonous oily liquid that turns yellow/brown in air. It is a naturally occurring organic compound obtained from plants."
*"nitrate"
NI30s
"A nitrate is a compound of a metal with a nitrate ion. Nitrates are salts of nitric acid."
*"nitric acid"
NI70s
"Nitric acid has the chemical formula HNO{\dn6 3}. It is a corrosive, caustic liquid."
*"nitrification"
NI80s
"The process of adding nitrogen to something."
*"nitrogen fixation"
NI90s
"The incorporation, mainly by micro-organisms in the soil, of nitrogen from the air (biological fixation) or inorganic substances applied to the soil (industrial fixation) into compounds that can be used by living organisms."
*"noble gases"
NO10s
"The inert, or noble, {\strike gases} are extremely unreactive {\strike gases}. The name noble {\strike gases} is now preferred as the {\strike gases} are now known to create compounds."
*"non phosphoric"
NO30s
"A substance that does not contain phosphorous."
*"non-flammable"
NO20s
"Flammable substances burst into flames easily; non-flammable substances do not."
*"nucleus"
NU10s
"The nucleus is the core of an atom and provides the atom's mass. It contains protons and neutrons and has a positive charge equal to the number of protons. This charge is balanced by the number of negative electrons."
*"nutrition"
NU20s
"The intake and use of food substances in plants, animals and humans."
*"nutritionally"
NU30s
"Referring to the intake and use of food substances by plants, animals and humans."
*"OPEC"
OP20s
"Organisation of Petroleum Exporting Countries. It consists of thirteen member countries who determine the price of crude oil and the quantities to be produced."
*"octane number"
OC10s
"A measure of the quality of petrol by measuring its ability to resist knocking of the engine when it is ignited."
*"oolitic"
OO10s
"Sedimentary rocks containing small spherical particles joined together in a fine mud matrix."
*"open pit"
OP30s
"A pit where the mineral being mined is dug from the earth at the surface, not from underground."
*"ore"
OR10s
"An ore is a material which occurs in nature and from which it is possible to extract an element."
*"organic"
OR20s
"Organic chemistry is the study of carbon compounds, such as alcohols and ethers. It does not include carbonates, hydrogencarbonates or the oxides of carbon."
*"organism"
OR30s
"Any living thing, including plants, animals, fungi and bacteria."
*"osteomyelitis"
OS10s
"Infection causing inflammation of the bone marrow."
*"oxidation"
OX10s
"A substance is said to undergo oxidation if subjected to any one of three processes: the gaining of oxygen; the loss of hydrogen; or the loss of electrons."
*"oxide"
OX20s
"An oxide is a compound formed when oxygen combines with one other element. This can either be a metal or a non-metal."
*"oxidise"
OX30s
"A substance is said to undergo {\strike oxidation} if subjected to any one of three processes: the gaining of oxygen; the loss of hydrogen; or the loss of electrons."
*"oxidised"
OX40s
"A substance is said to undergo {\strike oxidation} if subjected to any one of three processes: the gaining of oxygen; The loss of hydrogen; or the loss of electrons."
*"oxidising"
OX50s
"A substance is said to undergo {\strike oxidation} if subjected to any one of three processes: the gaining of oxygen; the loss of hydrogen; or the loss of electrons."
*"ozone"
OZ10s
"Ozone, a blue gas, is a poisonous allotrope of oxygen. Its molecules are triatomic (O{\dn6 3}). A layer of gas in the upper atmosphere protects the earth from ultra violet radiation emitted by the sun. In recent years the layer has thinned due to air pollutants."
*"Palaeozoic"
PA50s
"The period of geological time 590 to 250 million years ago, starting in the Cambrian Period and ending in the Permian period."
*"Phoenicians"
PH20s
"The peoples, from the end of the twentieth century BCE, living in Phoenicia, a narrow strip of land in the Eastern Mediterranean between the mountains of North Lebanon and the sea. Their major contribution to Western culture was the alphabet."
*"Precambrian"
PR40s
"The earliest geological era which dates from the formation of the earth (approximately 4600 million years ago) to 590 million years ago."
*"Prehistoric"
PR70s
"The period of time during which man developed before the invention of the written word."
*"particle"
PA40s
"A particle is a very small piece of a substance. Subatomic particles, such as protons, neutrons and electrons, are smaller than an atom."
*"pasteurisation"
PA60s
"The process of heating various foods, such as milk, to certain temperatures so as to destroy harmful micro-organisms within them."
*"pasteurise"
PA70s
"The process of heating various foods, such as milk, to certain temperatures so as to destroy harmful micro-organisms within them."
*"patent"
PA80s
"The legal grant to the inventor of something so that he/she has the sole right to make, use and sell the invention."
*"patented"
PA90s
"The legal grant to the inventor of something so that he/she has the sole right to make, use and sell the invention."
*"pelt"
PE70s
"The skin or hide of an animal with the hair or fur still attached."
*"pelts"
PE80s
"The skin or hide of an animal when it has had its hair/fur removed."
*"penicillin"
PE20s
"Penicillin is an antibiotic used in the treatment of many infectious diseases."
*"peptide bond"
PE90s
"The linkage formed between a carboxylic group and an amino group when two molecules containing these groups react together releasing one molecule of water."
*"perennial"
PE100s
"Something which lasts for over one or more years. Often refers to plants which continue growing for more than one year."
*"performance chemical"
PE30s
"A chemical, such as a plastic, which is manufactured to do a specific job."
*"pervious"
PE110s
"A substance through which other substances (often liquids or {\strike gases}) can pass."
*"pesticide"
PE120s
"A chemical which destroys harmful pests, often insects, which cause damage to agricultural crops."
*"petrochemical"
PE130s
"Any chemical or substance obtained from crude oil."
*"petrol"
PE140s
"A volatile flammable organic liquid used as a fuel in motor vehicles."
*"pewter"
PE60s
"Pewter, traditionally, was an alloy of tin and lead. The lead was added to increase the hardness of the tin but, because of its toxicity, antimony is now used in its place. It is used in tankards and in candlesticks."
*"phosphoric"
PH30s
"A substance containing the element phosphorous."
*"photoelectric"
PH10s
"There are two types of photoelectric cells: photoconductive cells; and photovoltaic cells. The electrical conductivity of photoconductive cells increases as the light grows brighter, photovoltaic cells convert light into electricity."
*"pitch"
PI10s
"A black solid obtained from the distillation of coal or wood tars or from crude oil."
*"plasma"
PL40s
"The liquid part of blood that contains various substances, such as proteins, dissolved in it."
*"plastic"
PL20s
"Any of a large number man made/synthetic polymer materials made from organic molecules. They can be shaped or moulded to a required design."
*"plasticity"
PL50s
"The ability of something to be shaped or moulded."
*"platelets"
PL60s
"Platelets are fragments of cells found in the blood. They are vital for clotting of the blood when wounding occurs."
*"pliable"
PL70s
"Something which can be easily moulded or bent."
*"plutonic"
PL80s
"A substance derived from volcanic magma which has subsequently cooled and solidified underneath the earth's surface."
*"plywood"
PL90s
"A board containing layers of wood compressed together with one layer of wood at right angles to the next one."
*"pollen"
PO50s
"Very fine grains produced in the anthers of flowers. They contain the male gametes of the plant."
*"pollinating"
PO60s
"The process of transferring pollen to the female parts of flowers, containing the female gamete, so that fertilisation can take place."
*"pollutants"
PO70s
"Substances introduced by man into the environment (land, air or sea) which are harmful or poisonous to life."
*"pollute"
PO80s
"The introduction, by man, of substances which can poison or harm the natural environment (land, air or sea)."
*"polymer"
PO90s
"A large molecule made up of many smaller, relatively simple molecules, called monomers, all chemically joined together. Polymers can be produced synthetically or naturally."
*"polymerisation"
PO100s
"A chemical reaction which joins many relatively small molecules together in long chains, forming polymers."
*"potash"
PO120s
"Potash can include a variety of compounds of potassium but mainly describes potassium hydroxide or potassium carbonate."
*"powder"
PO130s
"A solid substance in the form of many very fine particles."
*"precipitate"
PR50s
"The production of solid particles from solution by a chemical reaction. The particles of a solid produced from solution by a chemical reaction."
*"precipitators"
PR60s
"A substance which causes the production of a precipitate from solution."
*"propanone"
PR80s
"A colourless, volatile liquid. The simplest ketone containing a chain of three carbon atoms with the central carbon atom joined by a double bond to an oxygen atom."
*"prospecting"
PR90s
"Process of looking for or searching out something, often mineral ores or precious metals."
*"protein"
PR100s
"An organic compound of high molecular weight containing carbon, hydrogen, nitrogen and oxygen, found in all living organisms. Proteins are polymers made from joining together amino acids by peptide bonds."
*"proton"
PR20s
"A proton is a positively charged particle found in the nucleus of an atom. In every atom the number of {\strike protons} is always equal to the number of negatively charged electrons. This number forms the atomic number."
*"protons"
PR30s
"A {\strike proton} is a positively charged particle found in the nucleus of an atom. In every atom the number of protons is always equal to the number of negatively charged electrons. This number forms the atomic number."
*"putrefaction"
PU30s
"The process of decay and decomposition of dead organic matter."
*"pyrites"
PY10s
"A mineral ore containing yellow iron II sulphide. It resembles gold in appearance and is often called 'fool's gold'."
*"radiating"
RA10s
"{\strike Radiation} is the emission of energy in the form of electromagnetic waves. This term is also used to denote the energy itself."
*"radiation"
RA20s
"Radiation is the emission of energy in the form of electromagnetic waves. This term is also used to denote the energy itself."
*"radioactive"
RA40s
"A substance which has an unstable atomic nucleus which is stabilised by the release of electromagnetic waves or particles from the nucleus."
*"reaction"
RE20s
"A process involving change in which one or more compounds or elements (reactants) when put together form one or more different compounds (products)."
*"reactive group"
RE30s
"The part of a molecule which is the part which most often takes part in a chemical reaction."
*"recycling"
RE40s
"The use of a substance again after it has already been used once. The substance often goes through a process of purification before it is re-used."
*"refined"
RE50s
"A process during which substances have been purified or extracted from a mixture."
*"refining"
RE60s
"The process during which substances are purified or extracted from a mixture."
*"reflected"
RE10s
"When a wave rebounds off a surface it is said to have been reflected. Light is reflected by shiny surfaces. All electromagnetic radiation can be reflected, including heat and sound."
*"reforming"
RE70s
"The process of making straight chained alkanes into hydrocarbons with branched chains."
*"refraction"
RE80s
"The change of velocity/speed of a propagating wave (such as light or sound) when it moves from one medium to another, for example from air to water."
*"rennet"
RE90s
"An enzyme obtained from the stomach lining of calves. It is used for curdling milk during the manufacture of cheese."
*"residue"
RE100s
"The material remaining after something else has been removed from a substance."
*"resin"
RE110s
"A naturally occurring organic polymer, although it can be man made. It is a solid or semi-solid compound secreted from trees such as pines."
*"retted"
RE120s
"The separation of cloth fibres from their woody tissue of origin by soaking or moistening the tissue."
*"retting"
RE130s
"The separation of cloth fibres from their woody tissue of origin by soaking or moistening the tissue."
*"Silurian"
SI70s
"A geological period during the Palaeozoic era, dating from 435 to 408 million years ago. It was the period during which fish first started to appear."
*"salt"
SA20s
"A salt is a compound formed when some or all of the hydrogen in an acid is replaced by a metal. The reaction of zinc with hydrochloric acid, for example, would give hydrogen and the salt, zinc chloride. Salt is also a general name for the ionic salt, sodium chloride, (see also Science II Database of Materials)."
*"sedimentary"
SE40s
"A rock formed from the accumulation of layers of mineral fragments or organic remains compressed over time."
*"semiconductive"
SE10s
"{\strike Semiconductors} have conductive properties greater than those of an insulator, but less than those of a conductor. It is possible to change their level of conductivity by heating or adding impurities. They tend to be metalloids such as silicon or arsenic."
*"semiconductivity"
SE20s
"{\strike Semiconductors} have conductive properties greater than those of an insulator, but less than those of a conductor. It is possible to change their level of conductivity by heating or adding impurities. They tend to be metalloids such as silicon or arsenic."
*"semiconductor"
SE30s
"{\strike Semiconductors} have conductive properties greater than those of an insulator, but less than those of a conductor. It is possible to change their level of conductivity by heating or adding impurities. They tend to be metalloids such as silicon or arsenic."
*"semiconductors"
SE30s
"Semiconductors have conductive properties greater than those of an insulator, but less than those of a conductor. It is possible to change their level of conductivity by heating or adding impurities. They tend to be metalloids such as silicon or arsenic."
*"serpentine"
SE60s
"Magnesium silicate mineral rocks, the chief source of asbestos. These rocks are green to black in colour and contain snake-like patterns within them."
*"serpentinised"
SE70s
"A substance which has been converted into serpentine."
*"shale"
SH10s
"A sedimentary rock formed from clay. Some shales contain crude oil."
*"side effects"
SI60s
"Unwanted, undesirable effects on the body caused by the taking of a drug."
*"sinters"
SI80s
"The large particles, clumps or masses of a substance formed by heating metal powders at high temperatures and pressures."
*"slag"
SL20s
"The waste material obtained from the refining or smelting of metals. It contains sand, sulphur, calcium, phosphorous and other impurities."
*"smelting"
SM10s
"The extraction of a metal from its ore by heating."
*"solder"
SO80s
"Solders are alloys which melt readily, and are used to join metals. They usually contain lead and tin."
*"solid"
SO90s
"Solid is a state of matter in which the atoms or molecules of a substance are rigidly fixed in position. In liquids and {\strike gases} the bonds between the atoms and molecules are much looser. Solids have fixed shapes, masses and volumes."
*"solidifies"
SO130s
"A substance turning into a {\strike solid}, hard form."
*"soluble"
SO100s
"Soluble substances can be dissolved in a liquid."
*"solution"
SO110s
"A solution is a liquid mixture produced by dissolving a solid, liquid or gas in a solvent."
*"solvent"
SO120s
"A solvent is a liquid in which a solid, liquid or gas has dissolved to form a solution."
*"soy beans"
SO140s
"Soy beans or Soya beans come from a native Asian plants and contain relatively large amounts of protein."
*"specific gravity"
SP20s
"Another name for relative density. It is a ratio of the density of a substance compared with the density of a reference material. For liquids and solids the reference material is usually water."
*"stabilise"
ST50s
"To make something more {\strike stable} (less reactive)."
*"stable"
ST60s
"A substance that does not readily take part in a chemical reaction."
*"stagnant"
ST70s
"A name applied to still, stable, brackish water."
*"starch"
ST80s
"A carbohydrate / polysaccharide containing glucose units joined together. It is the main compound used for the storage of sugars in plants."
*"starches"
ST90s
"A carbohydrate/polysaccharide containing glucose units joined together. It is the main compound used for the storage of sugars in plants."
*"static"
ST100s
"Something which is not moving."
*"steel"
ST10s
"An alloy of which the main constituent is iron. Adding different elements to the iron produces steels of different properties. Stainless steel, for example, which contains iron, chromium and nickel, is very resistant to corrosion."
*"stratosphere"
ST110s
"A layer of air in the upper atmosphere between the troposphere and the mesosphere. In the stratosphere, the temperature increases with height."
*"sub-bituminous"
SU50s
"A substance resembling or partly containing bitumen."
*"subtropical"
SU60s
"Something that comes from the subtropics, the geographical area lying between the tropics and temperate areas having a rainy and a dry season."
*"sulphide"
SU40s
"A sulphide is a compound formed when sulphur combines with another element."
*"sulphuric acid"
SU70s
"A colourless oily liquid often used in the dilute form, otherwise known as 'oil of vitriol'. It is an inorganic acid, formula H{\dn6 2}SO{\dn6 4}."
*"synthesised"
SY30s
"A substance that is manufactured by humans."
*"synthetic"
SY40s
"A manufactured or man made substance."
*"taconite"
TA30s
"A low grade iron ore with an iron content of 25% or less."
*"tarnish"
TA20s
"When shiny metals corrode they are said to tarnish. Silver tarnishes when it reacts with the hydrogen sulphide present in the atmosphere, forming a layer of black silver sulphide."
*"tendon"
TE30s
"A cord of inelastic material which attaches muscles to bones in animals."
*"tendons"
TE40s
"Cords of inelastic material which attach muscles to bones in animals."
*"tensile strength"
TE50s
"The maximum force (often measured in Newtons) that can be applied to a substance before it breaks."
*"tetracyclines"
TE60s
"A type of antibiotic used against a wide range of bacterial infections."
*"thermoplastic"
TH10s
"A substance which loses its structure each time it is heated and therefore can be remoulded."
*"thermoset"
TH20s
"A substance which can be moulded the first time it is heated but then sets hard so that it cannot be remoulded on reheating."
*"toxic"
TO40s
"A harmful, poisonous substance."
*"toxicity"
TO50s
"The ability of a substance to be harmful or poisonous."
*"transparent"
TR30s
"A see-through, clear substance."
*"triatomic"
TR10s
"Triatomic molecules contain 3 atoms."
*"tropical"
TR40s
"Referring to the tropics, a geographical area where it is extremely hot and humid."
*"troy"
TR50s
"A system used for weighing precious stones."
*"vacuum"
VA20s
"Vacuums are spaces devoid of matter. They contain no atoms or molecules."
*"valency"
VA40s
"The amount of bonds with hydrogen an element, or ion of an element, can form."
*"vanadium"
VA50s
"A silvery white transition metal, symbol V. It has the valencies of +2 and +5 in its compounds."
*"viral"
VI30s
"Relating to something caused by viruses."
*"virus"
VI40s
"A microscopic pathogen consisting of nucleic acid surrounded by a protein coat. They cause many important diseases of plants and animals."
*"viruses"
VI50s
"A microscopic pathogen consisting of nucleic acid surrounded by a protein coat. They cause many important diseases of plants and animals."
*"viscosity"
VI60s
"A measure of the fluidity (the thickness or thinness) of a liquid or gas."
*"viscous"
VI70s
"A liquid (or gas) which is thick and sticky and does not flow well."
*"vitamin"
VI80s
"A chemical present in foods which, in small amounts, is required for proper functioning of the body."
*"vitamins"
VI90s
"A chemical present in foods which, in small amounts, is required for proper functioning of the body."
*"volatile"
VO20s
"A substance which readily changes from a solid or liquid into a vapour."
*"volatility"
VO30s
"The ability of something to change from a solid or liquid into a vapour."
*"volume"
VO10s
"Volume is the space occupied by a substance."
*"vulcanisation"
VU10s
"The process of adding sulphur to rubber to increase its hardness and durability. The sulphur causes cross linking between polymer chains in the rubber."
*"water"
WA10s
"A colourless, liquid compound of hydrogen and oxygen with the chemical formula H{\dn6 2}O. It is found in the atmosphere, lakes, oceans, rivers, rocks and living creatures, and is essential to life."
*"weathering"
WE10s
"The process by which rocks are broken down into smaller fractions due to physical processes caused by the weather."
*"wetting agent"
WE20s
"Any substance which lowers the surface tension of a liquid so that it can spread better over the surface of a solid or penetrate into a solid more easily."
*"whey"
WH10s
"The liquid part obtained by leaving milk to sour."
*"white spirit"
WH20s
"A colourless liquid mixture of hydrocarbons obtained from crude oil. It is a turpentine substitute and is used as a solvent for paints."
*"wild cat"
WI10s
"An exploratory process used for searching out crude oil and natural gas."
*"workability"
WO30s
"Applies to the ease with which a substance (often a metal) can be shaped."
*"yak"
YA10s
"An ox-like animal with long shaggy hair that is native to Tibet."
*"antibiotics"
AN70s
"Antibiotics are drugs derived from living organisms which can destroy other organisms. Penicillin, for instance, is derived from mould and can prevent the growth of many bacteria. (See also Science II Database of Materials.)"
*"asbestos"
AS10s
"Any of a group of fibrous, naturally occurring, extremely inert minerals, useful as insulators. (See also Science II Database of Materials.)"
*"aspirin"
AS30s
"A common pain relieving drug derived from salicylic acid which is produced in plants. (See also Science II Database of Materials.)"
*"bauxite"
BA70s
"A clay like rock containing hydrated aluminium oxides and used as the main ore for aluminium metal. (See also Science II Database of Materials.)"
*"bicarbonate of soda"
BI10s
"Sodium bicarbonate, NaHCO{\dn6 3}, is also called sodium hydrogencarbonate. The compound is used as a raising agent in cooking. (See also Science II Database of Materials.)"
*"bitumen"
BI30s
"A mixture of long chain hydrocarbons occurring naturally or obtained from crude oil. (See also Science II Database of Materials.)"
*"butane"
BU10s
"A member of the alkane group of organic compounds. It is a hydrocarbon containing four atoms joined by single bonds in a chain, attached to ten hydrogen atoms, with the formula C{\dn6 4}H{\dn6 10}. (See also Science II Database of Materials.)"
*"gypsum"
GY10s
"A naturally occurring mineral rock containing hydrated calcium sulphate and used as plaster of Paris. (See also Science II Database of Materials.)"
*"haematite"
HA20s
"A red-brown to black mineral rock containing iron oxide. It is used as the main ore of iron metal. (See also Science II Database of Materials.)"
*"keratin"
KE20s
"A structural, fibrous protein found in the hair, nails, fur, feathers, hooves and horns of animals. (See also Science II Database of Materials.)"
*"lignite"
LI10s
"A soft/brown form of coal containing about 70% carbon, with a high moisture content. (See also Science II Database of Materials.)"
*"mica"
MI10s
"A silicate mineral with a layered structure, that can be easily cleaved into thin sheets. (See also Science II Database of Materials.)"
*"pumice"
PU10s
"A light porous stone consisting of cooled volcanic lava. It is composed of silicate minerals and is often light enough to float on water. (See also Science II Database of Materials.)"
*"rayon"
RA30s
"A semisynthetic polymer derived from cellulose, used as a fibre for making clothes."
*"saccharin"
SA10s
"A very sweet substance with a very low calorific value, used as a replacement for sugar. (See also Science II Database of Materials.)"
*"silicon"
SI20s
"A metalloid element, symbol Si, belonging to group IV of the periodic table. It is very useful in the electronics industry as a semi-conductor. (See also Science II Database of Materials.)"
*"silicone"
SI30s
"A synthetic polymer containing chains of alternating silicon and oxygen atoms with the silicon atoms also joined to organic groups."
*"turpentine"
TU10s
"An oily liquid derived from the liquid resin of certain pine trees, used as a solvent for paint."
*"vinyl"
VI20s
"A name used to refer to the synthetic plastic polymer polyvinyl chloride, PVC, an addition polymer containing the monomer chloroethene (vinyl chloride). (See also Science II Database of Materials.)"
