Matter Definition  Anything that has mass and takes up space (has volume)  Matter is made up of atoms.

Example: Phase Changes Physical Change  A change in a substance that does not involve a change in the identity of the substance.

Other Physical Changes Reversible  Boil  Freeze  Melt  Condense Irreversible Break Split Cut Crush Physical changes can be classified as reversible or irreversible.

States of Matter  Solid  definite volume  definite shape  not easily compressed  particles packed in fixed positions Solid Copper

V1 Solid Videos: Video 1

Solids Video 2 V2 Structure of ice

States of Matter  Liquid  definite volume  indefinite shape  not easily compressed  particles close together, but not in fixed positions

Characteristics of Liquids  Flow - takes the shape of its container  Definite volume - intermolecular attractions keep particles close together

V3 Video 3 Liquid

States of Matter  Gas  indefinite volume  indefinite shape  easily compressed  particles are at great distances from one another  Vapor: describes the gaseous state of a substance that is generally a liquid or solid at room temperature. (ex: water vapor)

Characteristics of Gases  Expand to fill container  random motion, no attraction  Are fluid (like liquids)  no attraction  Very low densities.

Characteristics of Gases  Can be compressed  Almost no volume = lots of empty space  Flow  Undergo diffusion

V4 Gas State Video 4

States of Matter

Phase Changes  Melting Point (Freezing): The temperature at which a solid changes to a liquid OR a liquid changes to a solid  Boiling Point: The temperature at which a liquid changes to a gas OR a gas changes to a liquid.  Sublime: When a substance changes from a solid phase directly to a gas phase without becoming liquid - example, CO 2

V5 Evaporation & Condensation

Phase Change – Condensation -- Gas to Liquid Evaporation – Liquid to gas

Vaporization  Vaporization - the conversion of a liquid to a gas or vapor  Evaporation - vaporization when a liquid is NOT boiling  Vapor Pressure - force exerted by a gas above a liquid

Vaporization vs. Condensation How does temperature affect vapor pressure?

N2N2N2N2

What ’ s the Boiling Point?

Phase Changes