Key word Definition Chemistry: The Periodic Table A Russian scientist called Dmitri Mendeleev produced one of the first practical periodic tables (3) in the 19th Conductor A material that conducts charge or century. Before him was Döbereiner (1) and Newland’s table (2), both were arranged by atomic mass because there energy well. wasn’t the equipment to know about sub-atomic particles so they based it on mass. Density The mass of a material in a certain volume. He did 3 things: 3 1 Malleable Can be bent and shaped. 1. Grouped together elements with similar Ductile Can be pulled into wires. properties. 2. Put elements in order of 2 Sonorous Makes a ringing sound when hit. relative atomic mass.

3. Left gaps for unknown Properties of metals and non-metals elements & predicted their properties. Metals Non-metals

Good conductors of Poor conductors of The modern periodic table electricity and heat electricity and heat - Is a display of the Shiny Dull chemical elements, which are arranged by atomic High density Low density number, electron configuration, and Malleable Brittle recurring chemical Ductile properties.

Sonorous Not sonorous The modern periodic table is based closely on the ideas he used: • The elements are arranged in order of increasing atomic number • The horizontal rows are called periods Materials are used for particular jobs based on • The vertical columns are called groups their properties e.g. metal saucepan for cooking, • Elements in the same group are similar to each other plastic coating around electrical wires.