| A | B |
|---|
| melting | a solid turns into liquid by adding heat energy |
| freezing | a iquid turns into a solid by removing heat energy |
| vaporization | liquid turns into a gas at the boiling point of the substance |
| evaporation | liquid turns into a gas; can occur below the boiling point |
| condensation | gas turns into a liquid by taking heat energy away |
| sublimation | solid turns directly into a gas without turning into a liquid |
| deposition | gas turns directly into a solid |
| the four phases of matter | solid, liquid, gas, plasma |
| 2 examples of a physical change | tearing a piece of paper and melting an ice cube |
| 2 examples of chemical change | bicycle rusting and a campfire burning |
| difference between mass & weight | weight is dependant on gravity. mass stays same even when gravity changes |
| element | most simple, pure substance, made up of only 1 kind of atom |
| homogeneous mixture | the same throughout; example milk |
| heterogeneoous mixture | not the same throughout; example pepperoni pizza |
| compound | 2 or more elements that are chemically combined; example NaCl |
| photosynthesis | plants take in carbon dioxide, water and sunlight to produce sugar & oxygen |
| state of Law of Conservation of Mass | Matter is neither created nor destroyed |
| 3 subatomic particles that make up an aton | proton, neutron, electron |
| proton | located in nucleus and has a positive charge |
| neutron | located in nucleus and has a neutral charge |
| electron | located outside the nucleus and has a negative charge |
| solid | has definite shape and volume and particles vibrate |
| liquid | no definite shape, definite volume and particles flow |
| gas | no definite shape or volume and particles are random |
| plasma | no definite shape or volume and particles are random |
| what is the most common phase in the universe | plasma |
| metals | to the left of the "step"-malleable, ductile, have luster, good conductors of heat and electricity |
| nonmetals | to the right of the "step"- brittle, dull, poor conductors of heat & electricity |
| metalloids | line the "step", have properties of both netal and nonmetals |
| noble gases | the most stable element, they don not react with other substances |
| halogens | the most reactive nonmetal |
| alkali metals | the most reactive metals |
