Unit 1 (States of Matter) Chemistry

Matter

Anything that has mass and occupies space

States of matter

Solid, liquid, and gas

Particle

A tiny unit of matter such as an atom or molecule

Kinetic particle theory

Explains states of matter by the motion and energy of particles

Arrangement in solids

Regular, closely packed

Arrangement in liquids

Close together but disordered

Arrangement in gases

Far apart and randomly arranged

Motion in solids

Particles vibrate in fixed positions

Motion in liquids

Particles slide past each other

Motion in gases

Particles move quickly in random directions

Forces in solids

Strong forces hold particles tightly

Forces in liquids

Weaker forces allow particles to move

Forces in gases

Very weak forces, particles move freely

Shape of solids

Fixed shape

Shape of liquids

Takes the shape of container base

Shape of gases

Expands to fill container

Volume of solids

Fixed volume

Volume of liquids

Fixed volume

Volume of gases

Variable, depends on container

Compressibility of solids

Not compressible

Compressibility of liquids

Slightly compressible

Compressibility of gases

Highly compressible

Melting

Change from solid to liquid at melting point

Freezing

Change from liquid to solid at freezing point

Boiling

Change from liquid to gas at boiling point

Evaporation

Change from liquid to gas below boiling point

Condensation

Change from gas to liquid

Sublimation

Change from solid directly to gas

Heating curve

Graph showing temperature change and state change when heating

Cooling curve

Graph showing temperature change and state change when cooling

Latent heat

Energy absorbed or released during a state change without temperature change

Diffusion

Spreading of particles from high concentration to low concentration

Diffusion in gases

Fast due to large spaces and rapid motion of particles

Diffusion in liquids

Slower due to closer particles and greater forces

Effect of temperature on diffusion

Higher temperature increases diffusion rate

Effect of particle mass on diffusion

Lighter particles diffuse faster

Brownian motion

Random movement of particles caused by collisions

Pressure in gases

Caused by particles colliding with container walls

Effect of temperature on pressure

Higher temperature increases pressure (if volume is constant)

Effect of volume on pressure

Smaller volume increases pressure (if temperature is constant)