# Lesson 11 Phases of Matter Everything around is

• Slides: 28

Lesson 11 Phases of Matter • Everything around is matter • A state of matter is the physical form in which matter exists 1

Phases of Matter • There are four states or phases of matter 1. Solid 2. Liquid 3. Gas 4. Plasma 2

Phases of Matter • Matter often changes state when heat is added or taken away. 3

Solids, Liquids, Gases • On Earth most matter exists in three states a. Solid b. Liquid c. Gas 4

Solids, Liquids, Gases • Liquids: 5

Solids, Liquids, Gases • Gas: 6

Solids, Liquids, Gases • A gas will spread out to occupy all of the space available to it. • Both liquids and gases are referred to as fluids, because both have a tendency to assume the shape of whatever container holds them. 7

Solids, Liquids, Gases Property Solid Liquid Gas shape • Shape States of Definite Matter Their Properties shapeand No definite Volume Definite volume No definite volume Particle arrangement Densely packed Close Far apart Energy binding particles Very strong Strong weak 8

Particles and Phase • All matter is made up of particles called atoms and molecules. • The arrangement and motion of the particles that make up a substance determine its state 9

Solids • In a solid, particles are packed together quite closely and the energy binding these particles is very strong. • This prevents the particles from moving about freely. • The particles move by vibrating in their position. 10

Solids • This is what gives a solid a definite shape and volume * 11

Liquids • Particles in a liquid are less densely packed then those in a solid • The energy binding the particles of a liquid is also weaker than that in a solid • 12

Liquids • Particles in a liquid can move around and slide past one another. • The movement of the particles in a liquid prevents a liquid from having a definite shape. * Liquids do have a definite volume 13

Gases • The energy that binds particles in gases together is weak. • This allows the particles to move freely. * 14

Gases • The free movement of gas particles allows a gas to expand or contract to fit its container. • As a result, a gas lacks a definite shape and its volume is decided by the container that holds the gas. 15

Heat Affects the Phase of a Substance • When a substance takes in heat, its particles gain energy and move more quickly. • When a substance releases heat, its particles lose energy and move more slowly. 16

Heat Affects the Phase of a Substance • If enough heat is added or removed from a substance, a change in the state of the substance occurs. • Adding heat to a solid causes the particles of the solid to gain energy. * This causes the particles to move faster and farther apart. 17

Heat Affects the Phase of a Substance • If enough heat is added, the solid will change to a liquid. • When a substance changes from a solid to a liquid, it is melting • The temperature at which a solid begins to change to a liquid is called its melting point. 18

Heat Affects the Phase of a Substance • Each substance has its own melting point. • Particles in a liquid also move faster and spread apart when heat is added. • At a certain temperature, the particles gain enough energy that they begin to escape from the liquids surface and change to a gas. 19

Heat Affects the Phase of a Substance • The process in which a liquid changes to a gas is called vaporization. * The temperature at which a liquid brings vaporizing or changing to a gas is called boiling point 20

Heat Affects the Phase of a Substance • If heat is removed from a substance, its particles will lose energy, move more slowly and get closer together. * This can cause the substance to change states. 21

Heat Affects the Phase of a Substance • Condensation is the changing of a substance from a gas to a liquid. • The temperature at which a substance condenses is the same as the temperature at which it boils. 22

Heat Affects the Phase of a Substance • The difference is in the direction that the temperature has been moving, higher (boiling) or lower (condensing) 23

Heat Affects the Phase of a Substance • Freezing refers to a change from the liquid state to the solid state. • The temperature at which liquid begins to change into a solid is called freezing point. • The freezing point and melting of a substance are identical. 24

Heat Affects the Phase of a Substance • The term used depends on in which direction the temperature of the substance has been moving. • During a phases change, the temperature remains constant. • The temperature changes only after all of a substance has changed from one state to another. 25

Heat Affects the Phase of a Substance • The temperature will then rise or fall depending on whether heat is being added or removed from a substance. 26

Plasma • The fourth state of matter is plasma. • Plasma is a state of matter that forms when temperatures are high enough to remove electrons from their atoms. * 27

Plasma • Plasma forms when a gas is heated to such a high temperature that the electrons in its atoms gain enough energy to escape from their atoms. 28