1. Changes in states of matter pt.1

2. Change of state, AKA phase change
A change from one state of matter to another is a result of two things
Changes in the motion of the particles
Strength of the forces between the particles

3. Temperature
Temperature is a measure of the average kinetic energy of the particles in a material
Kinetic energy of an object increases as its speed increases
Temperature of a substances increases as the particles move faster and have more kinetic energy
Hot air vs. cold air, circulating air

5. Thermal energy
Thermal energy includes both kinetic energy and potential energy
Different states of matter have different amounts of thermal energy
Gas particles move faster and farther apart then solids
For any substance, the particles have most thermal energy in the gas state and the least amount in the solid state

6. Adding and removing thermal energy
Adding thermal energy to a substance can cause either an increase in temperature or a change in state
A change in state is when matter changes from one state to another
Solid to liquid, liquid to solid
Liquid to gas, gas to liquid
Gas to solid, solid to gas

9. Changes of state pt.2 review of states of matter

10. Melting Solid to a liquid
Heat a solid up, thermal energy flows into the solid until it reaches melting point
Melting point is the temperature at which the material changes from a solid to a liquid
Every substance has a unique melting point
Energy must be added to change from a solid to a liquid
Melting is an endothermic change (absorbs heat)

11. Freezing Liquid changes into a solid
Material cools, thermal energy flows out of the material
Freezing point is the temperature at which the liquid changes into a solid
Opposite of melting, exothermic reaction (releases heat)

12. Vaporization (boiling)
Liquid to a gas (vaporization)
For water, 100 degrees Celsius is boiling point, when it starts to evaporate
When vaporization occurs, attractive forces between particles become too weak to keep particles close to each. They spread out and move independently
Evaporations occurs at the surface of a liquid

13. Condensation Gas to a liquid
Large number of atoms /molecules clump together
On a hot day you might see drops of water on the outside of a glass of ice cold water
Dew in the morning is another example
Reverse of vaporization, exothermic reaction (releases energy)

14. Sublimation and deposition
Solid to a gas is sublimation, without going to liquid state
Dry ice is an example
Thermal energy must be added to a solid
Gas to solid is deposition
A form of crystallization
Frost that forms on a leaf is an example

16. Diffusion
Diffusion is the net movement of particles from an area of high concentration to an area low concentration
Can occur with the states of matter, either by themselves or when mixing
Diffusion video