| A | B |
|---|
| solid | particles packed tightly, stay in fixed positions |
| crystalline solid | particles in a regular, repeating pattern |
| amorphous solid | particles not arranged in a regular pattern |
| liquid | particles packed closely, but free to move |
| fluid | a substance that flows |
| viscosity | resistance of a liquid to flowing |
| gas | particles spread apart, filling all the available space |
| amorphous solid | a solid with no distinct melting point |
| physical change | an altered form, but not a change to a new substance |
| chemical change | forms a different substance with different properties |
| law of censervation of energy | energy can change from one form to another, no energy is lost |
| change in matter | occurs whenever energy is added or taken away |
| vaporization | occurs when a liquid gains enough energy to become a gas |
| boiling | when vaporization occurs inside the liquid and at the surface |
| melting | change of state from solid to liquid |
| freezing | change of state from liquid to solid |
| evaporation | vaporization only at the surface of a liquid |
| condensation | occurs when a gas loses enough thermal energy to become a liquid |
| sublimation | occurs when surface particles of a solid become a gas |
| chemical reaction | another name for a chemical change |
| thermal energy | total energy of the particles due to their movement or vibration |
| chemical energy | the potential energy stored in chemical compounds |
