Science 7 Name: Date: Unit C REVIEW Heat and Temperature 1. Read each sentence and circle the correct bold word. Scientists explain changes in state using the particle model of substances / matter. This model states that all matter is made up of extremely tiny / large particles. These particles are always still / moving. Adding heat / cold to particles makes them move faster. There is space / no space between the particles that make up matter. 2. Label each picture below as an insulator or conductor. 1
3. Decide which kind of heat transfer is being described in each of the situations below. conduction, radiation, or convection a) The fan helped push warm air toward the floor. b) The cement patio got very hot on summer afternoons. c) Air in the hot air popcorn popper helped heat up the kernels until they popped. d) When Janice left the metal spoon in the pot on the stove it became too hot to touch. e) The curling iron heated up quickly when plugged in. f) The bricks around the fireplace warmed up whenever fire was burning in the hearth. 4. Using technical terminology specify the correct change of state for each of the following statements. a) Frost appearing on windows. b) Ice cream running down a cone on a sunny day. c) Steam rising from a cup of hot tea. d) A pond becoming hard enough to skate on. e) Moisture forming on the side of a glass of cold water. 2
5. Label the diagram below with the correct state of matter and answer the following questions. a) Which particles are closest together? b) Which particles are farthest apart? c) Which particles vibrate? d) Which particles do not vibrate? e) Which particles do not move from place to place? f) Which particles move from place to place? g) Which particles move the most? h) Which particles become hot by conduction? i) Which particles become hot by convection? 3
6. Solar collectors are used for a) external combustion engines b) internal combustion engines c) active solar heating systems d) passive solar heating systems 7. Through which of the following will convection most likely occur? a) solids and liquids b) solids and gases c) fluids d) solids 8. What is the average temperature of a healthy body? 9. What is the temperature at which pure water freezes? 10. What is absolute zero? 11. What is the temperature at which water boils at sea level? 12. What is a comfortable temperature for a room? 13. What is happens the volume of most object as the thermal energy decreases? 4
14. Complete the sentences with the choices below. take their place faster solids conduction Sun move away vibrating convection gases more vibrate radiation bump heat a) Heat makes particles vibrate. b) The faster particles vibrate, the more they into other particles. c) When particles hit other particles, the other particles faster and give off more. d) Particles of are closest together. e) Particles of are farthest apart. f) Heat moves through solids by a method called. g) Heat moves throusgh liquids and gases by a method called. h) Heat is caused by particles. i) The faster the particles vibrate, the heat they give off. j) Convection currents are created when heated particles and other particles. k) Almost all of our heat energy comes from the. 5
15. Choose the correct word or term for each statement. a) Heat moves through solids by conduction / convection / radiation. b) Heat moves through liquids by conduction / convection / radiation. c) Heat moves through gases by conduction / convection / radiation. d) Heat moves through outer space by conduction / convection / radiation. e) Conduction does / does not need particles. f) Convection does / does not need particles. g) Radiation does / does not need particles. h) Heat that reaches the Earth is absorbed only / reflected only / absorbed and reflected. i) Dark colors mostly absorb / reflect heat. j) Light colors mostly absorb / reflect heat. k) When the thermal energy of a substance increases, its temperature increase / decreases. 16. Match the following terms below with the correct definitions. a substance takes up more space as kinetic energy and temperature increase the movement of particles in a substance energy that transfers from a substance with high kinetic energy to a substance with lower kinetic energy a substance takes up less space as kinetic energy and temperature decrease a substance expands because of an increase in thermal energy measure of average kinetic energy in a substance total kinetic energy of particles in a substance A. thermal expansion B. temperature C. heat D. expansion E. contraction F. thermal energy G. kinetic energy 6
Heat Transfer Word Scramble Unscramble each of the clue words. Copy the letters in the numbered cells to other cells with the same number. 7
Heat & Temperature Crossword Across 3. Dark or dull objects radiant energy. 4. Light or shiny objects radiant energy. 6. When heat is taken away from an object it will and get smaller. 7. The particles have between them. 9. Materials that allow an easy transfer of heat. 11. Temperature is the measure of the kinetic energy of an object. 13. Thermal energy is the kinetic energy of an object. 14. The transfer of heat between solids that are touching. 15. The 3 phases of matter are solid,, and gas. 16. When heat is added to an object it will and get bigger. 17. The particles are always. Down 1. Materials that do not allow an easy transfer of heat. 2. All matter is made of extremely tiny. 5. When you add heat to an object the particles move. 8. The transfer of heat when liquid or gas particles move from one area to another. 10. The transfer of heat which does not rely on the movement of particles. 12. The energy of movement. 8