Unit 7 Lesson 4 What Are the States of Water? Copyright © Houghton Mifflin Harcourt Publishing Company 1

Solids, Liquids, and Gases Unit 7 Lesson 4 What Are the States of Water? Solids, Liquids, and Gases Copyright © Houghton Mifflin Harcourt Publishing Company 2

Solids, Liquids, and Gases Unit 7 Lesson 4 What Are the States of Water? Solids, Liquids, and Gases Matter exists in different forms. Solids, liquids, and gases are three states of matter. Most matter on Earth is classified as one of these forms. Copyright © Houghton Mifflin Harcourt Publishing Company 3

Solids, Liquids, and Gases Unit 7 Lesson 4 What Are the States of Water? Solids, Liquids, and Gases A solid has a definite volume and shape. Your desk, book, pencil, and chair are all solids. Solids stay solid unless something, such as heat, changes them. Copyright © Houghton Mifflin Harcourt Publishing Company 4

Solids, Liquids, and Gases Unit 7 Lesson 4 What Are the States of Water? Solids, Liquids, and Gases A liquid has a definite volume but not a definite shape. Water, shampoo, and fruit juice are liquids. A liquid takes the shape of its container. Copyright © Houghton Mifflin Harcourt Publishing Company 5

Solids, Liquids, and Gases Unit 7 Lesson 4 What Are the States of Water? Solids, Liquids, and Gases A gas doesn’t have a definite volume or shape. Air is an example of a gas. A gas expands to take up all the space in a container. Copyright © Houghton Mifflin Harcourt Publishing Company 6

Unit 7 Lesson 4 What Are the States of Water? Copyright © Houghton Mifflin Harcourt Publishing Company 7

Unit 7 Lesson 4 What Are the States of Water? Water’s Forms Solid Water in the solid state has a definite volume and shape. The particles in solids are close together. They are moving but stay in the same spot. Copyright © Houghton Mifflin Harcourt Publishing Company 8

Unit 7 Lesson 4 What Are the States of Water? Water’s Forms Liquid Water in the liquid state has a definite volume but not a definite shape. Generally, the particles in a liquid are a bit farther apart than in a solid. They move around more, too. The particles slide past each other. Copyright © Houghton Mifflin Harcourt Publishing Company 9

Unit 7 Lesson 4 What Are the States of Water? Water’s Forms Gas When water is a gas, it is called water vapor. It doesn’t have a definite volume or shape. Particles in a gas are far apart. They are much farther apart than the particles in a liquid. They move quickly in all directions. Copyright © Houghton Mifflin Harcourt Publishing Company 10

Unit 7 Lesson 4 What Are the States of Water? Copyright © Houghton Mifflin Harcourt Publishing Company 11

Unit 7 Lesson 4 What Are the States of Water? Copyright © Houghton Mifflin Harcourt Publishing Company 12

Water’s Forms Which is a solid? Which is a liquid? Which is a gas? Unit 7 Lesson 4 What Are the States of Water? Water’s Forms Which is a solid? Which is a liquid? Which is a gas? Copyright © Houghton Mifflin Harcourt Publishing Company 13

Water Changes Form Freezing Unit 7 Lesson 4 What Are the States of Water? Water Changes Form Freezing A change of state occurs when matter changes from one state to another. As heat energy is removed from water, the particles slow down, get closer together, and lock into place. Water freezes. Copyright © Houghton Mifflin Harcourt Publishing Company 14

Water Changes Form Melting Unit 7 Lesson 4 What Are the States of Water? Water Changes Form Melting Adding heat energy causes ice to melt. Water melts when it changes from a solid to a liquid. During melting, particles speed up until they overcome the attractions that hold them in place. Copyright © Houghton Mifflin Harcourt Publishing Company 15

Water Changes Form Evaporation Unit 7 Lesson 4 What Are the States of Water? Water Changes Form Evaporation Evaporation is the process by which a liquid changes into a gas. When heat energy is added to liquid water, its particles speed up. Particles that gain enough energy enter the air as water vapor. Copyright © Houghton Mifflin Harcourt Publishing Company 16

Water Changes Form Condensation Unit 7 Lesson 4 What Are the States of Water? Water Changes Form Condensation When heat energy is removed from a gas, its particles slow down and clump together. Condensation is the process by which a gas changes into a liquid. Clouds form when water vapor condenses on particles of dust in the air. Copyright © Houghton Mifflin Harcourt Publishing Company 17

Unit 7 Lesson 4 What Are the States of Water? Copyright © Houghton Mifflin Harcourt Publishing Company 18