Phase Changes + Energy

Phase change

A change from one state of matter to another.

Melting

Solid → Liquid.

Freezing

Liquid → Solid.

Vaporization

Liquid → Gas.

Condensation

Gas → Liquid.

Sublimation

Solid → Gas.

Deposition

Gas → Solid.

Endothermic

A change that absorbs energy from the surroundings.

Exothermic

A change that releases energy to the surroundings.

Endothermic phase changes

Melting, vaporization, and sublimation.

Exothermic phase changes

Freezing, condensation, and deposition.

Melting energy

Energy increases because particles gain energy.

Freezing energy

Energy decreases because particles lose energy.

Vaporization energy

Energy increases because particles gain energy.

Condensation energy

Energy decreases because particles lose energy.

Sublimation energy

Energy increases because particles gain energy.

Deposition energy

Energy decreases because particles lose energy.

Melting particle spacing

Particles move farther apart.

Freezing particle spacing

Particles move closer together.

Vaporization particle spacing

Particles move much farther apart.

Condensation particle spacing

Particles move closer together.

Sublimation particle spacing

Particles move much farther apart.

Deposition particle spacing

Particles move closer together.

Melting density

Density decreases because particles spread farther apart.

Freezing density

Density increases because particles move closer together.

Vaporization density

Density decreases because particles spread far apart.

Condensation density

Density increases because particles move closer together.

Sublimation density

Density decreases because particles spread far apart.

Deposition density

Density increases because particles move closer together.

Temperature increases

Particles gain energy and generally move faster.

Temperature decreases

Particles lose energy and generally move slower.

Pressure increases

Particles are pushed closer together.

Pressure decreases

Particles have more space to move around.

Higher temperature

Usually causes particles to move faster.

Lower temperature

Usually causes particles to move slower.

Physical change

A change that does not create a new substance.

Chemical change

A change that creates one or more new substances.

Phase change

A physical change because the substance itself does not become a new substance.

Energy in an endothermic change

Energy goes into the substance.

Energy in an exothermic change

Energy leaves the substance.

Particle arrangement in a phase change

The particles themselves stay the same, but their spacing and movement change.

What happens when temperature increases

Particles move faster because they gain kinetic energy.

What happens when temperature decreases

Particles move slower because they lose kinetic energy.

What happens when pressure increases

Particles are forced closer together.

What happens when pressure decreases

Particles can spread farther apart.

Kinetic energy

The energy of motion; faster particles have more kinetic energy.