Thermal Energy

 Fill in the blanks.

An iron sheet will _________ when heated and will ________ when left to cool.

• expand, contract

• contract, expand

• gains heat, loses heat

• loses heat, gains heat

Fill in the blanks.

Copper has a higher coefficient of thermal expansion than iron. If a copper sheet is heated, it will ________ more than _________.

• contract, iron sheet

• expand, iron sheet

• contract, copper sheet

• expand, copper sheet

Which of not following are the three states of substances ?

• Liquid

• Solid

• Vapor

• Gas

Substances can change in state when heated. When a solid turns into a liquid, this is called ?

• Fusion

• Vaporization

• Sublimation

• Condensation

Substances can change in state when heated. When a liquid turns into a gas, this is called ?

• Fusion

• Vaporization

• Sublimation

• Condensation

Substances can change in state when it loses heat. When a gas turns into a liquid, this is called ?

• Freezing

• Vaporization

• Sublimation

• Condensation

Substances can change in state when it loses heat. When a liquid turns into a solid, this is called ?

• Freezing

• Vaporization

• Sublimation

• Condensation

Which of the following factors relates to the amount of heat that changes the state of a substance?

• Mass

• Specific heat of a substance

• Specific latent heat of a substance

• The change in temperature of a substance

Which of the following factors does not relate to the amount of heat that changes the temperature of a substance?

• Mass

• Specific heat of a substance

• Specific latent heat of a substance

• The change in temperature of a substance

What is the amount of heat needed to increase the temperature of water at 25 Celsius, with a mass of 30 g, to 50 Celsius (give that the specific heat of water is 4.2 kJ/kgK). Which of the following fomula to according ?

• Q=mcΔt

• Q=mL  

• Q=mcΔt+mL 

• Q=mcΔt+mL+mcΔt