1. Chapter 21 Review: Temperature, Heat and Expansion

2. What is temperature and how is it measured? Temperature is the measure of the average kinetic energy in a material. It is measured with a thermometer.

3. Which temperature scale has 100- degrees between the freezing point and boiling temperatures of water? Celsius temperature scale

4. What temperature scale do scientists use? The Kelvin temperature scale

5. On which temperature scale does water freeze at 32 degrees and boil at 212 degrees? The Fahrenheit temperature scale. Water freezes at 32-degrees and boils at 212- degrees.

6. What is heat? Heat is energy that flows between two things due to a temperature difference.

7. What is the unit of heat? The calorie or Calorie (1 kilocalorie) A calorie is the amount of heat energy needed to raise the temperature of 1-gm of water 1-degree Celsius. (1-kg of water for 1 kilocalorie)

8. How is the caloric content of food determined? By burning the food

9. True/False Heat travels from high to low temperature. True

10. When does thermal equilibrium occur? When two objects in thermal contact reach the same temperature.

11. Does matter contain internal energy or heat? Matter contains internal energy. Internal energy is the sum of all energies in a material.

12. Which has a lower specific heat capacity, water or sand? Sand-it heats up and cools down quickly when compared to water.

13. What is “specific heat capacity?” Specific heat is a measure of how much heat is needed to raise the temperature of a unit of mass of a substance by one degree. It also refers to whether a material has a high or low capacity to store internal energy.

14. What are some advantages of the high specific heat capacity of water? Bathing Cooking Cooling and heating systems Climate (west coast vs. east coast)

15. What happens to the temperature of a substance when the molecules move faster? The temperature increases because the average kinetic energy increases.

16. Why are sidewalks, decks and bridge surfaces built with gaps/spaces in them? To give them room to expand when they heat up.

17. How does matter respond when it’s heated? It expands

18. When a brass ring is heated, will the inside become larger or smaller? Larger, it expands outward

19. Cut a gap in the ring. Will the gap widen or narrow when heated? The gap will widen.

20. What is a bimetallic strip and where are they used? A bimetallic strip is made of two different metals that have different expansion rates. They are used in thermostats.

21. At what temperature is water the densest? 4-degrees Celsius

22. What happens to water at 4-grees Celsius when it’s heated? Cooled? It expands. It’s less dense because its volume increases.

23. Why/How do fish survive in a deep lake when it freezes over in the winter? The lake freezes from the top down. The densest water is at the bottom. The water temperature at the bottom is 4-degrees Celsius.