Learn on PengiAmplify Science (California) Grade 7Chapter 2: Investigating Energy and Phase Change

Lesson 2: Energy Transfer Mechanisms

Key Idea.

Section 1

Heating Increases Molecular Speed

Key Idea

Heating is the process of transferring energy into a substance. As molecules absorb this incoming energy, their kinetic energy increases.

This boost in energy causes them to move faster. If they gain enough speed, they may eventually break out of their rigid structures, leading to a phase change.

Section 2

Cooling Decreases Molecular Speed

Key Idea

Cooling is not the addition of "coldness," but the removal of energy. When energy is transferred out of a substance, the molecules lose kinetic energy.

As a result, they slow down. With less momentum, the molecules settle into more stable, orderly arrangements, potentially causing a gas to condense or a liquid to freeze.

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

Heating Increases Molecular Speed

Key Idea

Heating is the process of transferring energy into a substance. As molecules absorb this incoming energy, their kinetic energy increases.

This boost in energy causes them to move faster. If they gain enough speed, they may eventually break out of their rigid structures, leading to a phase change.

Section 2

Cooling Decreases Molecular Speed

Key Idea

Cooling is not the addition of "coldness," but the removal of energy. When energy is transferred out of a substance, the molecules lose kinetic energy.

As a result, they slow down. With less momentum, the molecules settle into more stable, orderly arrangements, potentially causing a gas to condense or a liquid to freeze.

Overview

Lesson overview

Review the lesson summary and core properties without leaving the current page.

Overview

Section 1

Heating Increases Molecular Speed

Key Idea

Heating is the process of transferring energy into a substance. As molecules absorb this incoming energy, their kinetic energy increases.

This boost in energy causes them to move faster. If they gain enough speed, they may eventually break out of their rigid structures, leading to a phase change.

Section 2

Cooling Decreases Molecular Speed

Key Idea

Cooling is not the addition of "coldness," but the removal of energy. When energy is transferred out of a substance, the molecules lose kinetic energy.

As a result, they slow down. With less momentum, the molecules settle into more stable, orderly arrangements, potentially causing a gas to condense or a liquid to freeze.