Chapter Menu Chapter Introduction Lesson 1Lesson 1Solids, Liquids, and Gases Lesson 2Lesson 2Changes...

Chapter Introduction

Lesson 1 Solids, Liquids, and Gases

Lesson 2 Changes in State

Lesson 3 The Behavior of Gases

Chapter Wrap-Up

What physical changes and energy changes occur as matter goes from one state to another?

• How do particles move in solids, liquids, and gases?

• How are the forces between particles different in solids, liquids, and gases?

Solids, Liquids, and Gases

• solid

• liquid

• viscosity

• surface tension

Solids, Liquids, and Gases

• gas

• vapor

Two factors determine the state of matter:

Describing Matter

• the motion of the particles of the matter

• the forces between the particles of the matter

• All particles have random motion; movement in all directions and at different speeds.

• Collisions of particles usually change the speed and direction of the particles’ movements.

Describing Matter (cont.)

• In some matter, the particles move slowly.

• The particles vibrate in place.

• The attractive forces between the particle are strong.

Describing Matter (cont.)

• In other matter, the particles move faster and slip past each other.

• The distance between the particles increases.

• The attractive forces between the particles are weaker.

Describing Matter (cont.)

• In other matter, the particles move very fast.

• The distance between the particles is great.

• The attractive forces between the particles are very weak.

Describing Matter (cont.)

In summary:

Describing Matter (cont.)

• As the motion of the particles slows, the particles move closer. The attractive forces become stronger.

• As the motion of the particles increases, the particles move farther apart. The attractive forces become weaker.

Describing Matter (cont.)

• A solid is matter that has a definite shape and a definite volume.

• The attractive forces between the particles in a solid are strong and pull them close together.

Solids

Solids (cont.)

Describe the movement of particles in a solid and the forces between them.

Solids (cont.)

• Different particle arrangements give materials different properties.

• A diamond is a crystalline solid with particles arranged in a specific, repeating order. Charcoal is an amorphous solid with randomly arranged particles.

• A liquid is matter with a definite volume but no definite shape.

• Liquids flow and can take the shape of their containers.

Liquids

The particle motion in a liquid is faster than the particle motion in a solid.

Liquids (cont.)

Viscosity is a measurement of a liquid’s resistance to flow.

Liquids (cont.)

Dr. Parvinder Sethi Scott Thomas/Getty Images

• Molecules at the surface of a liquid have surface tension, the uneven forces acting on the particles on the surface of a liquid.

• The surface tension of water enables certain insects to walk on the surface of a lake.

Liquids (cont.)

Describe the movement of particles in a liquid and the forces between them.

Liquids (cont.)

• A gas is matter that has no definite volume and no definite shape.

• Compared to the particles in the solid and the liquid states, the particles in gases are far apart.

Gases

• In a gas, the forces of attraction between the particles are not strong enough to keep the particles close together.

• Because the particles in gas are moving quickly, the distance between particles increases, and the attractive forces between particles decreases.

• The gas state of a substance that is normally a solid or a liquid at room temperature is called vapor.

Gases (cont.)

How do particles move and interact in a gas?

Gases (cont.)

• In some matter, particles can only vibrate in place. The particles are close together, and there are strong forces among them.

• In other matter, the particles are far enough apart that particles can flow past other particles. The forces among these particles are weaker than those shown above.

• In another group of matter, the particles are far apart and there is little or no attraction among the particles.

A. solid

B. plasma

C. liquid

D. gas

Which describes matter with a definite volume but no definite shape?

A. closer together

B. farther apart

C. slower moving

D. tightly packed

Compared to a liquid, which best describes the particles of a gas?

Which term refers to the gas state of a substance that is a solid at room temperature?

A. plasma

B. surface tension

C. vapor

D. viscosity

1. Particles moving at the same speed make up all matter.

2. The particles in a solid do not move.

Do you agree or disagree?