Thermal Energy

Conduction can only occur between two objects when –

• one object is less dense than the other.
• both objects are in physical contact with each other.
• one of the objects is made of a metal.
• both objects are exactly the same temperature.

Which material is the best conductor of heat?

• glass
• styrofoam
• metal
• wood

Why does a metal lawn chair get hot in the sun when the grass sitting in the same sunlight remains cool to the touch?

• Heat travels easily through plants but not metals.
• Heat travels easily through both plants and metals.
• Heat travels easily through metal objects but not through plants.

Which of the following is an example of conduction?

• Solar energy warming a room.
• Heat rising from the coils of a stove.
• Hot air drying a wet towel.
• Heat moving from a clothes iron to a shirt.

The particles of a gas move ____than the particles of the same substance in the liquid or solid state.

• faster
• slower
• same speed

Heat will always transfer from the ___________ object to the ________ object.

• The hottest object to the coolest object.

• The coolest object to the hottest object.

• The solid object to the liquid object.

• The liquid object to the solid object.

Jenny poured some hot chocolate into a cup and stirred it with a metal spoon.  She noticed the spoon was really warm.  What is the best explanation for this?

• The spoon is a conductor.
• The spoon reflects heat.
• The spoon is an insulator.
• She touched the spoon first and waited to touch the cup.

Convection is heat transfer by-

• Touch an object
• The heating and cooling of a fluid
• Electromagnetic Waves

Radiation is heat transfer by-

• Touch
• Circles
• Waves

In what direction do hot liquids and gasses move?

• Side to Side
• Down
• Up
• Back and Forth