States of Matter

Kinetic Theory

• Definition: How particles in matter behave

• All Matter is composed of small particles.

• Particles are in constant random motion.

• Particles collide with each other and walls of their containers

Thermal Energy

• Definition: Total energy of a material’s particles; causes particles to vibrate in place.

Kinetic Energy• Definition: Temperature of the substance,

or how fast the particles are moving.

- Lower Temperature: Slower Motion

Four States of Matter

• Solid

• Liquid

• Gas

• Plasma

• Energy Level?

SolidSolid

•Has a stable, definite shape

•Has a definite volume

•Particles are packed closely together

•Cannot move freely, can only vibrate

•Energy and temperature are very low

•Can only change their shape by force

LiquidLiquid

•Does not have a definite shape

•Shape is determined by the container in which it is held

•Volume is definite

•Particles are farther apart than in solids, and can slide past each other easily

•Energy and temperature, in comparison to a solid, are higher

GasGas

• Has an indefinite, unstable shape

• Volume is determined by the container that is closely sealed

• Particles are far apart from each other, and can move around quickly

• Energy and temperature are the higher than those of both solids and liquids

PlasmaPlasma

• High Temperature gas with balanced positively and negatively charged particles.

• Made up the most state in the universe

• Examples: Fluorescent light, lightning, stars

How particles behave….

Changes of State/Phase

Phase Changes

Original State New State Names of Change

Solid Liquid Melting

Liquid Solid Freezing

Liquid Gas Evaporation

Gas Liquid Condensation

Solid Gas Sublimation

Physical Change

• Change that alters the substance without changing its chemical composition

• Breaking, Bending, Cutting• Can be a reversible process• Examples:

– Dissolving salt in water;– Denting a car bumper;– water to ice or vapor;– Glass break– Ice cream melts

Chemical Change• Occurs when one or more substance change

into one or more new substance• Energy is released (exothermic) or absorbed

(endothermic)• Indicator: Change in color and odor• Examples:

– Burning candle, – Cooking– Melting sugar– Metal Rust– Food Disgetion– Photosynthesis

FLUID

• Definition: A substance that can flow and take the shape of the container in which it is held.

• Examples:

Liquids and Gases.

Liquid vs GasExample

/Property

Liquid Gas

Example Water Air

Shape No definite shape

No definite shape

Volume No definite volume

No definite volume

Particles Arrangement

Close Far apart

Energy binding particles

Strong Weak

Properties of Fluid

• Density

• Pressure

• Buoyancy

• Viscosity

• Definition: A measure of the mass of a substance per unit volume:

• Does not dependent on size.

• Density of a substance change as its phase change.

• Usually solid being denser.

Density

Mass (g or kg)Volume (liter, c.c. (cm3))

Pressure

• Definition: Force exerted on a unit area of a substance.

• Pressure changes Gas density, but NOT Liquids.

• Thus, density can be used to identify a liquids (e.g. fancy drinks in layers)

• SI Unit: Pascal (Pa)

Force (N)Area (cm2, m2)

Pressure

• Pascal’s principle – pressure applied to a fluid is transmitted throughout the fluid. Example: hydraulic machines.

Buoyancy

• Definition: the ability of a fluid to exert an upward force on an object that is immersed in it.

• Float

- Weight of object < Buoyant Force

- Density of object < Density of water

• Sink – Weight of object > Buoyant Force

Buoyancy

• How does an aircraft carrier made of steel (heavier than water) can stay afloat in the sea?– Clues: Density and Pressure

Viscosity

• Definition: A liquid’s resistance to flow

• Determined by molecular structure

• Increased temperature will lower viscosity.

Behavior of Gases

• Pressure

• Boyle’s Law

• Charles’s Law

• Gay-Lussac’s Law

Pressure

• Measured in units called pascal (Pa)

• Collisions of particles in air result in atmospheric pressure.

Boyle’s Law

• Relates to pressure and volume

• Volume decreases as pressure increases.

• Pressure multiplied by volume is always equal to a constant if the temperature is constant.

Charles’s Law

• Relates to volume and temperature

• At a constant pressure, volume increases as temperature increases.

• At a constant pressure, volume decreases as temperature decreases.

Gay-Lussac’s Law

• Relates pressure and temperature; at a constant volume, as temperature increases, pressure increases.