Expansion and Contraction

Short name and class

During all the time, the atoms..

• Not moving

• Moving around

• Vibrating

When atoms are supplied with heat, vibration

• Increases

• Decreases

• No change

When heat is removed, vibration of atoms

• Increase

• Decrease

• No change

When atoms vibrate more, they

• become further apart

• become closer together

• not changing distance

When atoms become closer with each other,

• They expand

• They contract

Expansion can be

• a problem

• a benefit

• problem and benefit

Expansion can be a problem in

• Power cable

• Railway tracks

• Fire alarm

Contraction can be a problem in

• Power cable

• Railway tracks

• Fire alarm

Expansion can be a benefit in

• Power cable

• Railway tracks

• Fire alarm