Phase Changes

Phase Changes

Multiple Select

What are the 3 states of matter we are most familiar with?

• solid

• liquid

• gas

• Texas

The Law of Conservation of Energy states that energy cannot be created nor destroyed, but only changed from one form to another.

Multiple Choice

Energy cannot be ___________ or destroyed.

• used

• created

• recycled

Thermal energy must be added to change from a solid to a liquid to a gas.

Thermal energy must be removed to change phase from a gas to a liquid to a solid.

Poll

Thermal energy probably means ________

• heat

• electricity

• movement

• Melting – solid changing into a liquid

• Vaporization – liquid changing into a gas

• Ionization – gas changing into a plasma

• Neutralization – plasma changing into a gas

• Condensation – gas changing into a liquid

• Freezing – liquid changing into a solid

• Sublimation – direct change of a solid to a gas or a gas to a solid without going to a liquid state

A phase change graph is a temperature vs. time graph displaying the phases of matter and the temperature at which phase changes occur.

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Multiple Choice

On this graph, as time increases, temperature...

• increases

• decreases

Multiple Choice

The diagonal lines on a phase change graph represent...

• states of matter

• phase change from one phase of matter to another

Multiple Choice

The flat lines on this graph represent

• phases of matter

• phase changes from one form of matter to another

As matter changes phase, thermal energy is absorbed or released until all particles of matter have changed. Therefore, the temperature remains constant.

Multiple Select

During phase change...

• temperature remains the same

• the matter is transforming from one form to another

• temperature increases

• energy is created

The melting point is the temperature at which a solid becomes a liquid.

The boiling point is the temperature at which a liquid becomes a gas.

The condensation point is the temperature at which a gas becomes a liquid.

 Condensation point = Boiling point

The freezing point is the temperature at which a liquid becomes a solid.

 Freezing point = Melting point

Heating and cooling systems regulate temperature by transferring energy.

A heating system is any device or process that transfers energy to a substance to raise its temperature.

 ex. Rubbing hands together, human       body, furnace, reptiles basking in       the sun, solar panels.

A cooling system is any device or process that transfers energy as heat out of a substance to lower its temperature.

 ex. Refrigerator, air conditioner,          condensation, sweating, heat             pumps.

Multiple Choice

Heating systems put heat INTO a system and cooling systems...

• take heat out

• put cold in