Physical Science Chapter 2

Matter

Anything that takes up space and has mass.

Mass

Measure of amount of matter in an object.

Kilogram

Basic unit for measuring mass.

Volume

Amount of space an object occupies.

Displacement Method

Used to calculate volume of irregular objects.

Density

Mass divided by volume of a substance.

Physical Properties

Measured without changing substance's identity.

Chemical Properties

Measured by changing a substance's identity.

Physical Changes

Changes that do not alter substance's identity.

Chemical Changes

Changes that alter substance's identity.

Element

Pure substance that cannot be broken down.

Compound

Substance with two or more elements combined.

Mixture

Combination of two or more pure substances.

Homogeneous Mixtures

Uniform throughout; also called solutions.

Heterogeneous Mixtures

Not uniform throughout; distinct components.

Colloids

Contain small particles that do not settle.

Suspensions

Contain large particles that settle out.

Law of Conservation of Mass

Matter is neither created nor destroyed.

Crystalline Solids

Particles arranged in a repeating pattern.

Amorphous Solids

Particles arranged randomly without a pattern.

Viscosity

Resistance of a liquid to flow.

Pressure

Force exerted by gas particles on surfaces.

Pascal

Unit of pressure; one newton per square meter.

Kinetic Theory of Matter

States particle energy determines state of matter.

Boyle's Law

Pressure increases as volume decreases at constant temperature.

Charles's Law

Volume increases as temperature increases at constant pressure.

Amonton's Law

Pressure increases as temperature increases at constant volume.

Freezing

Liquid turns into a solid

Liquid particles must release energy

Point at which an object freezes is called a freezing point

Melting

Solid turns into a liquid

Solid particles must absorb energy

Point at which an object melts is called the melting point

Boiling

Heat is added to liquid until it bubbles and turns into a gas

Liquid particles must absorb energy

Evaporation

Liquid turns into gas without boiling (no bubbles)

Liquid particles must absorb energy

Evaporative cooling

When the most energetic liquid particles evaporate the remaining particles are cooler than they were before

Condensation

Gas turns into liquid

Gas particles must release energy

Point at which an object experiences condensation is called the dew point

Sublimation

Solid turns into gas without first becoming a liquid

Deposition

Gas turns into a solid without first becoming a liquid