Phase Changes

All changes in the state of matter of a substance requires

• vibration
• water
• permission
• energy

Change from gas to liquid...

• condensation
• evaporation
• expansion
• movement

A gas

• has a definite shape but no definite volume
• has a definite volume but no definite shape
• has fast-moving particles

In a laboratory experiment a student was using Styrofoam cups and foil to reduce the energy lost during an exothermic reaction.  The reaction constantly had a temperature probe in it.  Towards the end of the reaction the student noticed the temperature in the cups was going down (opposite what they thought is should).  The student concluded that the energy was destroyed within the system.  This student's reasoning violates what law?

• Law of Conservation of Mass
• Law of Enthalpy
• First Law of Thermodynamics
• Law of Heat Transfer

Phase change from solid to gas 

• endothermic
• exothermic

7. All phase changes (changing states) requires energy to be added or taken away.

• True
• False

Change from Liquid to Solid is called ...

• fusion

• Freezing

• sublimation

• evaporation

When the temperature of matter decreases the particles ...

• speed up and move farther apart
• speed up and move closer together
• slow down and move farther apart
• slow down and move closer together

What type of reaction is shown in the picture?

• endothermic
• exothermic
• potential energy
• kinetic energy

What happens to particles when energy is added (heated)?

• They speed up and spread out

• They slow down and compress

• They stop moving

• They move closer together and speed up