Physical Changes Changes of State

Changes from one state to another (ie Changes from one state to another (ie. Solid to liquid, liquid to gas, etc…) Molecules themselves do NOT change What does change is the arrangement of molecules and space between them Basic substance remains the same

to Gas Liquid

Melting

Iron melts. It was solid, now it is liquid.

Freezing

Water freezes. It was liquid, now it is solid.

Evaporation Includes boiling

The water also changed from liquid to gas when it boiled. Water evaporates from the car. It was water, now it is vapor (a gas) in the air. The water also changed from liquid to gas when it boiled.

Sublimation

The dry ice (frozen carbon dioxide) immediately converts from solid to gas. You can see vapors coming out of the pan.

Condensation

Warmer air condenses on the cooler bottle of liquid Warmer air condenses on the cooler bottle of liquid. Air changed directly from gas to liquid. Where did the water droplets come from in this picture? Inside or outside the bottle?

Deposition

Frost occurs when air changes directly to a solid Frost occurs when air changes directly to a solid. Frost is like ice on the windshield that was once a gas.