From Atoms to Materials

13.3 The Periodic Table A. Development of the Periodic Table (p. 30) B. Periods and groups in the Periodic Table (p. 32) 1. In the modern Periodic Table, elements are arranged in order of increasing atomic numbers. 2. In the Periodic Table, each horizontal row is called a period, and each vertical column is called a group. C. Similarities between elements of the same group (p. 34) D. Different reactivity in a group (p. 38) 3. Elements in the same group have similar chemical properties, but they may have different reactivity. 13.4 Compounds and mixtures A. Compounds (p. 43) 1. A compound is a pure substance made up of two or more elements chemically combined together. 2. A compound may be broken down into its constituent elements. 3. The properties of a compound are different from those of its constituent elements. B. Mixtures (p. 49) 4. A mixture consists of two or more pure substances that are not chemically combined together. C. Physical changes and chemical changes (p. 49) 5. During a physical change, no new substance is formed. 6. During a chemical change, one or more new substances are formed. Chapter Review 108 © United Prime Educational Publishing (HK) Limited 2024 All rights reserved; no part of this publication may be reproduced, photocopied, recorded or otherwise, without the prior written permission of the Publisher. Sample