Matter exists in four states - solid, liquid, gas, and plasma - depending on temperature. In solids, particles vibrate in place and maintain a definite shape and volume. In liquids, particles can move around each other while maintaining a definite volume. In gases, particles separate and move freely in all directions without definite shape or volume. Plasma is an ionized gas state not found naturally on Earth. Phase changes between states require or release energy.

9. Energy Temp solid liquid melts gas (vaporization) condenses freezes + energy - energy Phase Changes

11. Energy Temp solid liquid melts gas (vaporization) Heat of Fusion Heat of Vap.

12. Solid-Liquid Phase Change Melting- Change of a solid to a liquid. Occurs when a substance absorbs energy (heat). Melting point - Temp. at which a solid changes to a liquid. ex. H 2 O = 0 0 C

13. Liquid-Solid Phase Change Freezing- Change of a liquid to a solid. Occurs when a liquid loses heat (energy). Freezing Point- The temp. at which a substance changes from a liquid to a solid. ex. H 2 O = 0 0 C

14. Liquid-Gas Phase Change Vaporization- The change of a substance from a liquid to a gas. Occurs when the particles of a liquid absorb energy (heat). Evaporation- When vaporization takes place at the surface of the liquid.

15. Liquid-Gas Phase Change Boiling- Process in which particles inside a liquid as well as those on the surface of a liquid change to gas. Boiling Point- Temp. at which a substance changes from the liquid phase to the gas phase.

16. Gas-Liquid Phase Change Condensation- A change from the gas to the liquid phase. Occurs when a substance in the gas phase loses energy (heat).

17. Solid - Gas Phase Change Sublimation- When the surface particles of a solid escape directly into the gas phase.

18. The Ideal Gas Laws: Boyle’s Law- The volume of a fixed amount of gas varies inversely with the pressure of a gas. As the pressure increases the volume of the gas decreases and vice-versa. P 1 V 1 = P 2 V 2

19. The Ideal Gas Laws: Charles’s Law- As the temp. of a gas increases the volume increases. As the temp. of a gas decreases the volume decreases. T 1 V 2 = T 2 V 1

20. Boyle’ Law With a fixed amount of gas, when the ___________ is increased, the volume ____________. When the ___________ is decreased, the volume ___________. pressure decreases pressure increases

21. Charle’s Law With a fixed amount of gas, when the _______ is increased the volume ___________. When the _______ is decreased the volume ___________. temp. increases temp. decreases