Unit 6 Lesson 4 States of Matter Copyright © Houghton Mifflin Harcourt Publishing Company 1

Unit 6 Lesson 4 States of Matter Florida Benchmarks SC.8.N.1.1 Define a problem from the eighth grade curriculum using appropriate reference materials to support scientific understanding, plan and carry out scientific investigations of various types, such as systematic observations or experiments, identify variables, collect and organize data, interpret data in charts, tables, and graphics, analyze information, make predictions, and defend conclusions. SC.8.N.3.1 Select models useful in relating the results of their own investigations. Copyright © Houghton Mifflin Harcourt Publishing Company 2

Unit 6 Lesson 4 States of Matter Florida Benchmarks SC.8.P.8.1 Explore the scientific theory of atoms (also known as atomic theory) by using models to explain the motion of particles in solids, liquids, and gases. LA.8.4.2.2 The student will record information (e.g., observations, notes, lists, charts, legends) related to a topic, including visual aids to organize and record information, as appropriate, and attribute sources of information. Copyright © Houghton Mifflin Harcourt Publishing Company 3

Unit 6 Lesson 4 States of Matter Particles in Motion How do particles move in solids, liquids, and gases? The kinetic theory of matter states that all matter is made of tiny particles that are in constant motion. The state of matter is determined by how much particles move and how often they bump into each other. Copyright © Houghton Mifflin Harcourt Publishing Company 4

How do particles move in solids, liquids, and gases? Unit 6 Lesson 4 States of Matter How do particles move in solids, liquids, and gases? A solid is a substance with a definite volume and shape. Particles are close together and do not move freely. A liquid is a substance with definite volume but not a definite shape. A gas is a substance that does not have a definite volume or shape. Copyright © Houghton Mifflin Harcourt Publishing Company 5

Unit 6 Lesson 4 States of Matter Shape Up! How does particle motion affect the properties of solids, liquids, and gases? Particles in a solid vibrate but remain in fixed positions. Solids cannot easily change shape or volume. Liquids take the shape of their container. Particles in a liquid are close together but not tightly arranged. Copyright © Houghton Mifflin Harcourt Publishing Company 6

Unit 6 Lesson 4 States of Matter How does particle motion affect the properties of solids, liquids, and gases? Particles in liquids slide past each other, creating flow. Particles in gases are far apart. The space between gas particles can change easily. Gases take on the shape of their container. Copyright © Houghton Mifflin Harcourt Publishing Company 7

Unit 6 Lesson 4 States of Matter How does particle motion affect the properties of solids, liquids, and gases? What state of matter is shown in the image below? How do you know? Copyright © Houghton Mifflin Harcourt Publishing Company 8

What happens when substances change state? Unit 6 Lesson 4 States of Matter What happens when substances change state? The process in which a solid becomes a liquid is called melting. As a solid is heated, if the vibrations in the particles are fast enough, the particles break loose and slide past one another. Copyright © Houghton Mifflin Harcourt Publishing Company 9

What happens when substances change state? Unit 6 Lesson 4 States of Matter What happens when substances change state? When temperatures of a liquid are lowered, causing a solid to form, it is called freezing. Lower temperatures cause the particles to move slowly enough for the attractions between them to cause the liquid to become a solid. Copyright © Houghton Mifflin Harcourt Publishing Company 10

What happens when substances change state? Unit 6 Lesson 4 States of Matter What happens when substances change state? Water freezes at 0 °C, but other substances can freeze at room temperature. When substances lose or gain energy, one of two things can happen to the substance: its temperature can change or its state can change. Copyright © Houghton Mifflin Harcourt Publishing Company 11

Unit 6 Lesson 4 States of Matter Making Glass Glass blowing is the shaping of glass by blowing air into a blob of molten glass from the end of a blowpipe. Glass is made by heating a mixture of sand, soda ash, limestone, and other ingredients until it melts. Melted glass can be cooled, and it will change to the solid state. Copyright © Houghton Mifflin Harcourt Publishing Company 12