SX05_BkK_AdRdStdyWkBk.fm Page 22 Monday, April 18, 2005 8:09 AM Name Date Solids, Liquids, and Gases ■ Class Adapted Reading and Study Changes of State (pages 48–53) Changes Between Solid and Liquid (pages 49–50) Key Concept: At its melting point, the particles of a solid substance are vibrating so fast that they break free from their fixed positions. At its freezing temperature, the particles of a liquid are moving so slowly that they begin to form regular patterns. • When a solid changes to a liquid, the solid is melting. Solid ice melts in warm temperatures and forms liquid water. • When a solid gains thermal energy, the particles of the solid move in place faster. When enough energy is added, the particles break away from their places. • When a liquid changes to a solid, the liquid is freezing. Freezing is just the reverse of melting. Liquid water freezes in very cold temperatures and forms ice. • When a liquid loses thermal energy, the particles of the liquid slow down. Over time, the particles move into fixed places. Then, the liquid becomes solid. Answer the following questions. Use your textbook and the ideas above. 1. Read each word in the box. In each sentence below, fill in the correct word or words. melting freezing thermal energy a. When a liquid changes to a solid, the liquid is . b. When a solid changes to a liquid, the solid is . © Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved. 22 SX05_BkK_AdRdStdyWkBk.fm Page 23 Monday, April 18, 2005 8:09 AM Name Date Solids, Liquids, and Gases ■ Class Adapted Reading and Study 2. Fill in the words in the table below to show the relationship between energy and the movement of particles. Changes Between Solid and Liquid Change of State Thermal Energy Particles Move Melting added or gained b. Freezing a. slower 3. Is the following sentence true or false? When a liquid becomes a solid, it gains thermal energy. Changes Between Liquid and Gas (pages 50–52) Key Concept: Vaporization takes place when the particles in a liquid gain enough energy to form a gas. Condensation occurs when particles in a gas lose enough thermal energy to form a liquid. • The change from a liquid to a gas is called vaporization (vay puhr ih ZAY shun). At high temperatures, water changes to water vapor. When a puddle of water disappears on a hot, sunny day, the water has changed to water vapor. • When a liquid gains thermal energy, the particles of the liquid move faster. When enough energy is added, the particles spread far apart. Then, the liquid becomes a gas. © Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved. 23 SX05_BkK_AdRdStdyWkBk.fm Page 24 Monday, April 18, 2005 8:09 AM Name Date Solids, Liquids, and Gases ■ Class Adapted Reading and Study • The change from a gas to a liquid is called condensation (kahn dehn SAY shun). When water vapor cools, it becomes liquid water. Dew on the grass in the morning is water vapor in the air that has cooled and become a liquid. • When gas particles lose thermal energy, they slow down. As the particles slow down, the particles move closer together and form a liquid. Answer the following questions. Use your textbook and the ideas on page 23 and above. 4. Look at the pictures below. One shows a puddle of water on a sunny day. The other shows drops of dew on grass. Circle the letter of the picture in which vaporization is occurring. a. b. 5. Read each word in the box. In each sentence below, fill in one of the words. make gain lose a. Vaporization takes place when liquid particles thermal energy. b. Condensation takes place when gas particles c. thermal energy. © Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved. 24 SX05_BkK_AdRdStdyWkBk.fm Page 25 Monday, April 18, 2005 8:09 AM Name Date Solids, Liquids, and Gases ■ Class Adapted Reading and Study Changes Between Solid and Gas (page 53) Key Concept: During sublimation, particles of a solid do not pass through the liquid state as they form a gas. • The direct change from a solid to a gas is called sublimation (suhb luh MAY shun). In sublimation, the solid never changes to a liquid. When snow seems to disappear without melting, sublimation has taken place. • Sublimation takes place when particles on the surface of a solid gain enough thermal energy to break away. The particles have enough energy to spread far apart and form a gas. Answer the following question. Use your textbook and the ideas above. 6. Is the following sentence true or false? In sublimation, a solid becomes a liquid first, then a gas. © Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved. 25
© Copyright 2025 Paperzz