The periodic table presents the elements arranged in atomic number order. Elements are
organized in periodic groups based on the number of valence electrons of the element, and are classified as metals, nonmetals, and metalloids.
It was Dmitrii Mendeleev and Lothar Meyer who created and published the first successful periodic tables in 1870, although they had worked independently of each other. Mendeleev based his table on chemical properties; Meyer, on physical properties. Mendeleev proposed a table with columns of related elements, yet his table was incomplete; he intentionally neglected to fill each space. These voids, however, eventually lead to the discovery of new elements. Put simply, Mendeleev accurately predicted the properties of the undiscovered elements, realizing the periodic relationships of the elements around them on this table. As a result, the periodic table is an organizational tool and an important source of information about each element, as well as the trends of the elements.
INSTRUCTIONS
Elemental Properties
A variety of commonly studied properties of the elements are available for examination using this computerized periodic table. The characteristics of each element can be obtained by one of four methods:
1. Click on the element in the periodic table.
2. Type the name of the element in the text box and press return.
3. Type the element's symbol in the box and press return.
4. Type the element's atomic number in the box and press return.
The elemental properties to be examined include:
Atomic Weight Ionization Energy
Density Covalent Radii
Melting Point Ionic Radii
Boiling Point Isotopes
Electron Affinity Common Charges
Electronegativity
Periodic Trends
Atomic Number Graphs plot a property as a function of the atomic number for all 105 elements. To view an atomic number graph, (1) click on the Atomic Number Graphs menu item, then (2) select the property of interest.
The atomic number vs. property graph appears in place of the periodic table. To graph a different property, click on the Atomic Number Graphs menu again and select another property. To recall the periodic table, click on the graph.
Graph Period and Graph Group menu items allow plots of elemental properties as a function of a group or period, respectively. These plots show trends across or down the periodic table. To make periodic plots, click on the property of interest under the Graph Period or Graph Group menus. Secondly, choose a period or group to plot by double clicking on any element in the period or group of interest. Alternatively, click the right mouse button on an element. Once again, the plot appears in place of the periodic table. Click on the graph to return to the periodic table.
A useful method for comparing trends of periodic properties is to overlay graphs. The graphs will automatically overlay while sequentially selecting different groups or periods. If you do not wish to overlay graphs you can choose the Clear Plot button after viewing each plot. Graphs of different properties cannot be overlaid; if you attempt this you will be notified of this limitation. In addition, you cannot overlay group plots with period plots.
References:
Atomic Molar Mass, Density, Melting Point, Boling Point, Electron Affinity, Ionization Energy,
Ionic Radii, Number of Isotopes taken from CRC Handbook of Chemistry and Physics, 71st Ed.,
CRC Press, Boston, 1991
Covalent Radii taken from Lange's Handbook of Chemistry, 11th Ed., John A. Dean, Editor,
McGraw-Hill Book Company, 1973
Electronegativity taken from Chemistry and Chemical Reactivity, 3rd Ed., John C. Kotz and Paul
