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- @Heat is another form of:
- Energy
- Work
- Power
-
- @A liquid is heated until its molecules move very much faster, and the distance between them becomes very large. This process could describe:
- Boiling
- Melting
- Condensation
-
- @Which of the following has the highest temperature?
- Filament of a light bulb
- A swimming pool full of warm water
- The water in a boiling kettle
-
- @The heat needed to change a solid to a liquid is called:
- Latent heat
- Energy
- Fusion
-
- @A burn from steam is worse than a burn from boiling water because:
- The temperature of steam can be more than 100°C
- Steam is a gas
- Steam molecules move more slowly
-
- @When a puddle of water slowly disappears over a period of time is called:
- Evaporation
- Sublimation
- Diffusion
-
- @A container has a liquid in it. Which one of the following will NOT speed up evaporation?
- Having more liquid in the container
- Heating the liquid
- Blowing across the liquid
-
- @When a liquid evaporates, what other effect might you notice?
- The liquid left behind is cooler
- The liquid left behind expands
- The liquid left behind is not changed in any way
-
- @Liquids cool after evaporation because:
- only slower moelcules with less energy are left behind
- all the molecules left behind speed up
- the molecules left behind get smaller
-
- @An electric motor wastes 20% of the energy supplied by producing heat. How efficient is the motor?
- 80%
- 120%
- 20%
-
- @Adding salt to boiling water does what to its boiling point?
- Raises it
- Lowers it a little
- Lowers it a lot
-
- @On a high mountain water boils at a temperature:
- below 100°C
- above 100°C
- at 212°C
-
- @In winter, water pipes sometimes burst because:
- Ice expands when it forms
- Ice is cold
- The substance the pipes are made of shrinks and cracks
-
- @Ice is taken from a fridge and heated. Its temperature is constantly checked. What do the readings show?
- The temperature remains around 0°C until all the ice is melted, and then rises
- The temperature immediately, and steadily, rises
- The temperature quickly rises to 4°C and then remains constant until all the ice has melted
-
- @A fridge works on the principle of:
- Evaporation
- Convection
- Sublimation
-
- @What effect does pressure have on the boiling point of a liquid?
- Increasing pressure causes it to rise
- None at all
- Lowering the pressure raises the boiling point