1. Energy and Matter Changes in State Chapter 8 Lesson 2 Mr. Nigh Science 7

2. Kinetic Energy Kinetic Energy is the energy an object has due to its motion Temperature is a measure of the average kinetic energy of all particles in a substance SolidLiquidGas

3. Potential Energy The greater the distance between particles, the greater the chemical potential energy of the particles

4. Thermal Energy Thermal Energy is the total potential and kinetic energy in an object When Thermal energy is added to added to a substance, the particles move faster and faster. Substances may change their state of matter

5. REMEMBER: particles are always in motion, even in solids. Because the particles in a solid are bound together, they do not move from place to place-they vibrate As a solid heats up, the particles vibrate faster until they break loose and slide past each other-in other words turn into a liquid.

6. Melting The temperature at which a specific solid becomes a liquid is its melting point.

7. Freezing is the process by which a liquid becomes a solid A frozen substance does not have to have an extremely cold temperature, some substances are frozen at room temperatures (ie. candles, pop cans)

8. The temperature at which a specific liquid becomes a solid is its freezing point. The freezing point of a substance is the same as the melting point At temperatures below this point the substance is a solid, above this point the substance is a liquid.

9. Vaporization Vaporization is the change in the state of a liquid into a gas. The kinetic energy of particles increases until the liquid reaches its boiling point During boiling, liquid vaporizes at the surface and within the liquid.

10. Evaporation is another process by which a liquid becomes a gas It usually occurs at the surface of a liquid The fastest moving particles at the surface can break away from the liquid and escape to become gas particles

11. When you cool a gas it loses energy. As the particles move more slowly, the attractions among them cause water droplets to form Condensation is the process by which a gas changes its state to become a liquid

12. Sublimation Under certain conditions, solids can lose particles through a process similar to evaporation. When solids change directly to a gas, it is known as sublimation. Dry ice or frozen carbon dioxide sublimates in normal atmospheric conditions

13. Deposition Deposition is the change from a gas gas directly into a solid