1. Vocabulary Unit 2 (7 terms)

2. 1. Chemical Reaction The process by which a chemical change occurs. In a chemical reaction atoms are rearranged and new materials are formed.

3. 2. Energy the ability to do work. Examples: –"It takes twice as much energy to lift a weight twice as high." –"The fire roared as the energy in the wood was released by burning." –"The bowling ball transferred some of its kinetic energy to the pins."

4. 3. Energy Transformation The process of transforming one form of energy to another. There are many different machines that convert one energy form into another.

5. Energy Transformation Examples Fuel cells (Chemical energy → Electricity) Geothermal power (Heat → Electricity) Heat engines, such as the internal combustion engine used in cars or the steam engine (Heat → Electricity) Hydroelectric dams (Mechanical energy → Electricity) Lamp (Chemical energy → Heat and Light) Microphone (Sound → Electricity) Nuclear reactor (Nuclear energy → Electricity) Solar cells (Light → Electricity) Loudspeaker (Electricity → Sound) Steam engine (Heat → Mechanical energy) Wave power (Mechanical energy → Electricity) Windmills (Wind energy → Electricity or Mechanical energy)

7. 4. Chemical Energy that part of the energy in a substance that can be released by a chemical reaction.

8. 5. Mass The amount of matter contained within an object.

9. 6. Closed System A closed system means that none of the products or reactants can escape to the outside environment. It is like being inside a bottle with a cork in the top. Guess what the largest closed system is?

10. 7. Conservation of Mass A principle in physics stating that the total mass of an closed system is unchanged by interaction of its parts.

11. What does this cartoon have to do with conservation of mass?