From Atoms to Materials

13.5B M ore on the history of discovery and use of metals Exploree The order that metals were discovered and used by humans depends on: • their abundance in the Earth’s crust; and • the ease of extraction from their ores. Checkpoint 13.5B 1. The time when a metal was discovered and used in human history is related to: • its (a) in the Earth’s crust; and • the ease of (b) from its (c) . 2. Circle T for a true statement and F for a false one. (a) The Iron Age came before the Copper Age. T / F (b) Aluminium was discovered late in history because of its low abundance. T / F 3. Read the following text and answer the questions. (a) In what form does sodium exist in oceans? (b) Suggest a reason for its late discovery. The element sodium is very abundant in the Earth’s crust. It exists in large volumes in rocks and oceans. Sodium was first discovered in the 19th century. Search for more information about the history of discovery and use of metals. Present your findings as a timeline. 74 © 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