| A | B |
|---|
| protons | positive charge: particle |
| nuetron | particle with no charge |
| atoms | smallest particle of an element that still has properties of that element |
| electrons | have negative charge can join, leave or be shared among atoms |
| What do the numbers in the formula mean? | the 2 after the H shows that water has 2 hydrogen atoms |
| hydrogen ++ oxygen | H20 (water) |
| solid phase | definite shape and volume particles are vibrating in place |
| melting | when a solid turns into a liquid --melt and freeze temperature always the same--particles can move more and flow past another |
| liquid phase | definite volume, no shape--will take the shape of whatever it is in--melts and freezes at 0 degrees celcius--things heat up and they move fast and spread out when particles move slower and are closer together |
| Which substance expands when it is frozen? | water (H20) |
| Gas phase | no definite shape or volume |
| Phase | state of matter due to the motion and arrangement of its particles (molecules or atoms) |
| Which substance expands when frozen? | water |
| How can liquids become gas? | through evaporation or boiling |
| evaporation | particles move upward and form vapor |
| boiling | at high temperatures molecules through liquid move upward and form vapor--different liquids have different boiling points |
| Which take up more space... gases or liquids? | gases |
| condensation | gas particles cool, slow down and stick together |
| mixture | when different materials are placed together but do not bond to form compounds |
| solutions | a special mixture in which substances are spread out evenly and will not settle |
| How are mixtures and solutions alike? | they both do not form compounds |
| How are solutions and mixtures different? | because solutions dissolve into one another and one spreads out evenly |
| How are atoms identified? | by the number of protons |
