Transfer of Thermal Energy

Your finger feels cold when you dip it into ice water. This is because ___________________.

• Temperature flows from your finger to the ice water.

• Thermal energy flows from your finger to the ice water.

• Thermal energy flows from the ice water to your finger.

Solids conduct thermal energy faster than liquids and gases because

• their particles are packed closely together.

• their particles vibrate more vigorously.

• their particles can move freely at high speeds.

Conduction can

• only occur in solids.

• only occur in fluids.

• occur in solids and fluids.

Convection can

• occur only in solids.

• occur only in fluids.

• occur in solids and fluids.

Convection current is formed because of

• changes in density of fluids.

• changes in mass of fluids.

• changes in weight of fluids.

When a fluid is heated, it

• expands, becomes denser, and sinks

• expands, becomes less dense, and rises

• contracts, becomes less dense, and rises

When a fluid is cooled, it

• expands, becomes denser, and sinks.

• contracts, becomes less dense, and sinks.

• contracts, becomes denser, and sinks.

What is the main process that transfers thermal energy from the Sun to the Earth?

• conduction

• convection

• radiation

Which process does not require a medium to transfer thermal energy?

• conduction

• convection

• radiation

Which type of surface is the best absorber of radiation?

• black, rough surface

• white, smooth surface

• black smooth surface