internal energy

How do particles in a solid move

Do not move from place to place, but vibrate

Movement of liquid particles

Can move around each other

Movement of gas particles

Move extremely rapidly

What do particles Ina solid liquid and gas all have

Kinetic energy

What do particles also have

Potential energy (intermolecular forces and chemical bonds)

What is the internal energy

The energy stored in a system by the particles

The total kinetic energy and potential energy of all the particles (atoms and molecules) that make up a system

When is internal energy really important

During changes of state

What happens if we beat a solid

Internal energy increases

At some point the solid can turn into a liquid (melting)

What happens if we heat a liquid

Internal energy increases

At some point the liquid will turn into a gas (boiling)

What happens if we cool the gas

Decreases internal energy

At some point the gas turns back into a liquid (condensation)

What happens if we cool the liquid

Decreases internal energy

At some point the liquid turns to solid (freezing)

What is it called when a solid turns directly into a gas

Sublimation

What is sublimation

When a solid turns directly into a gas

Example of sublimation

Carbon Dioxide does that at room temperature and pressure

What stays the same as changes of state takes place

Mass is always conserved, we’re not adding or taking away any particles

What type of change is a change of state

A physical change, meaning if we reverse the change, the material recovers it’s original properties

What is evaporation

When a liquid turns to gas but only on the surface of the liquid. Only particles on surface have enough energy to turn into gas