From Atoms to Materials

orbit 軌跡 John Dalton ( 道爾頓 ) Solid sphere model (1803) An atom is a solid sphere. It cannot be divided into smaller particles. Diagram: J. J. Thomson ( 湯姆森 ) Plum pudding model (1904) An atom is a positively charged big sphere, with negatively charged electrons embedded in it like plums in a pudding. The numbers of positive and negative charges are equal. Diagram: Niels Bohr ( 玻爾 ) Bohr model (1913) The nucleus is surrounded by electrons, which move in different orbits*. The numbers of positive and negative charges are the same. Diagram: Erwin Schrödinger ( 薛定諤 ) Electron cloud model (1926) An electron may appear anywhere in a certain region around the nucleus. Dotted regions represent positions where electrons are likely to appear. Diagram: You may search for extra information to help your drawing! More to Read A few early atomic models proposed by scientists are introduced below. Based on the descriptions, draw appropriate diagrams for these models in the space provided. Unifying concept Through advances in research and technology, scientists have gained deeper knowledge about atoms. Based on new evidence , new atomic models were proposed one after another. Development of atomic models 13 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