States of Matter Chapter 3

States of Matter Physical forms in which a substance can exist Matter is always in motion, but the speed of these particles will vary

Solids Have a definite shape and volume Crystalline: orderly arrangement Ex. Iron, Diamond, ice Amorphous: no ordered arrangement Ex. Rubber, wax

Liquids Change shape, but not volume Surface Tension: force acting on particles to give a spherical drop/shape Viscosity: liquids resistance to flow Ex. Honey has a high viscosity versus water

Gas Change both shape and volume Pressure is the amount of force on a given area Boyles Law - the volume of a gas increases as the pressure decreases (at a constant temperature) Charles Law - the volume of the gas increases as temperature increases

Plasma Has no shape or volume and particles have broken Ex. Artificial plasma include fluorescent lights. Natural plasma include lightning during severe weather or the aurora borealis “Northern Lights”

Change of State A conversion of a substance from one physical form to another Energy of a substance changes, changing the temperature (measure of the speed of a substances particles) Transfer of energy is heat

1. Melting Change of state from solid to liquid Melting points vary with substances and are characteristic properties Energy is absorbed to overcome particle attraction

2. Freezing Change from a liquid to solid Because it’s reverse to melting, freezing and melting point occur at the same temperature (0oC) Energy is removed

3. Vaporization Change from liquid to gas Boiling - vaporization that occurs throughout a liquid (Ex. Water b.pt. = 100oC) Evaporation - vaporization that occurs at the surface of a liquid Pressure affects boiling point Ex. Lower boiling point in Denver, CO because less atmosphere = less pressure to break apart particles…takes longer to boil pasta!

5. Sublimation Change from a solid to a gas Ex. Dry ice used in theatres or coolers, ice cubes in your freezer get smaller over time