PARTIAL EXAM

7TH

Review:

1. The production of the gastric juices that the stomach uses in the digestive process depends to some extent on the emotional state of the individual. fear and Sadness reduce the amount of gastric juices in the stomach, which is why we often don't fell hungry when we are afraid or unhappy.

2. Energy is the ability to cause matter to move of change.

3. The energy in food is changed into the energy of motion and body heat, and it is used to build and repair body cells.

4. Growth and activity depend on storage and release of energy.

5. All temperature changes are essentially transfers of energy.

6. Energy comes in many forms, including light, heat, sound, electrical, nuclear, and chemical energy.

7. There are two types of energy: Potential energy is stored energy (potential because it has the potential to make something happen), and Kinetic energy is energy of motion (the energy an object has because of its motion).

8. Energy can be converted from one form to another. ALL forms of energy can be converted into other forms. energy transformation is a change in energy from one form to another.

9. Energy can be changed from one form to another, but it CANNOT be created of destroyed. During energy transformations, the total amount of energy remains the same because energy cannot be created or destroyed. some of the energy in a transformation is changed into heat that does no work.

10. Energy converters CANNOT be 100% efficient because they lose useful energy to friction while they are operating.

11. Efficiency is the ratio of waste energy to effective work of a system.

12. Chemical energy is energy stored in the arrangement of atoms and molecules. Is the potential energy stored in chemical bond. Example: Fuel, food, wood, match.

13. Electrical energy is the energy of charged particles.

14. Nuclear energy is released during fission ( Fission is by splitting atomic nuclei) and fusion (fusion is by forcing nuclei together) reaction. Nuclear energy is by far the MOST CONCENTRATED form of energy. Example: Atomic bomb, Star.

15. Energy that makes the sun shine, comes from the fusion of hydrogen nuclei to make helium.

16. Radiant energy takes the form of electromagnetic waves. Sunlight takes only 8 minutes to travel from the sun to Earth, and distance of 150 million kilometers. Light travels 300,000 km/s.

17. Thermal energy is the total kinetic and potential energy of the atoms and molecules within a substance. Thermal energy is heat. Example: volcano.

18. Fluorescent lamp save 5 TIMES more energy than using a normal bulb (incandescent lamp).

19. Energy changes include an INPUT, CONVERTER, and OUTPUT.

Answer.

1. Two example for each form of energy.

2. Two examples for each type of energy.

3. Efficiency of the energy converter. p 326. Human, hydroelectric plant, electric motor, furnace, incandescent and fluorescent lamp.

4. Input and Output of 5 different converters.

5. Energy make over. 5 examples of converting device and the energy change.