6th Grade Science

Chapter 18 Thermal Energy

Notes Section

18.2Chihuly at the New York Botanical Garden

• What is heat?• Heat is the transfer of thermal energy due to a

temperature difference between two objects. • How does heat move?• Heat always moves from a object with a higher

temperature to an object with a lower temperature.

Key Questions 1

Heat is the transfer of thermal energy due to a temperature difference between two objects.

Heat Transfers from the boiling water to the ice water.

• What is conduction?• Conduction is the transfer of thermal energy when

substances are in direct contact.• What is radiation?• Radiation is the transfer of thermal energy by

electromagnetic waves.

Key Questions 2

The Tadpole Galaxy

• Heat flows from your warmer hand to the colder ice, and the slow-moving molecules in the ice move faster.

Conduction

• As a result, the ice becomes warmer and melts.

Conduction is the transfer of thermal energy when substances are in direct contact.

• Heat is transferred from the Sun to Earth by radiation.

Radiation

• Heat transfer by radiation occurs when energy is transferred by electromagnetic waves.

• The transfer of thermal energy by radiation can occur in empty space, as well as in solids, liquids, and gases.

• What is convection?• Convection is the transfer of thermal energy by the

movement of matter. • What is a thermal conductor?• A thermal conductor is a material in which heat

moves easily – metals.

Key Questions 3

The Sombrero Galaxy

Thermal Conductors – Cookware, Copper Plumbing, Steel

• What is a thermal insulator?• A thermal insulator is a material in which heat is

NOT easily transferred.• What is the specific heat of a substance?• The specific heat of a substance is the amount of

heat needed to raise the temperature of 1 kg of a substance by 10C.

Key Questions 4

Thermal insulators – Space Shuttle Tiles, Coats, Insulation

1. Explain why materials such as plastic foam, feathers, and fur are poor conductors of heat

2. Explain why the sand on a beach cools down at night more quickly than the ocean water.

3. If a substance can contain thermal energy, can a substance also contain heat?

4. Describe how heat is transferred from one place to another by convection.

5. Explain how a blanket keeps you warm.

Questions Section 18.2