From Atoms to Materials

Fig. 13.10 Silicon Semi-metals The element silicon* is shown on the right. Some of its physical properties are listed in Table 13.5. Compare these properties with those of metals and non-metals. What do you notice? Appearance (at room conditions) grey, shiny solid Melting point and boiling point high Ductility and malleability not ductile, not malleable, brittle Electrical conductivity only conducts electricity within a certain temperature range Table 13.5 Some physical properties of silicon Some elements show properties in between those of metals and non-metals. They belong to a group of elements called semi-metals . In addition to silicon, other examples of semi-metals include boron* and germanium*. semi-metal 半金屬 silicon 硅 boron 硼 germanium 鍺 metalloid 類金屬 chip 晶片 Snapshot A computer chip Semi-metals are also known as metalloids*. • Elements can be classified into metals, non-metals and semi-metals, according to their physical properties. • Semi-metals show properties in between those of metals and non-metals. Uses of semi-metals Semi-metals have many uses. For example, silicon is an important material for making computer chips*. You can find a complete list of all metals, non-metals and semi-metals in the Periodic Table in the Appendix of this book. 23 13 From Atoms to Materials © 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