The Periodic Table is one of the most powerful organising tools in all of science. Far from being a simple list of elements, it encodes a vast amount of chemical information in its structure, and once you learn to read it, it becomes possible to predict the properties of elements you have never encountered before.

We open the chapter by looking at how the Periodic Table is arranged, and how the position of an element in terms of its period and group reflects its electronic configuration. We then explore the chemical properties of three groups in detail. Group I, the alkali metals, are highly reactive metals whose reactivity increases down the group as the outer electron becomes easier to remove. Group VII, the halogens, are reactive non-metals that exist as diatomic molecules, and whose reactivity decreases down the group. We look at the displacement reactions of halogens with halide ions as a direct demonstration of this trend. We also examine the transition elements, which sit in the middle block of the Periodic Table and are characterised by their high densities and melting points, their ability to form coloured compounds, and their widespread use as catalysts.

The chapter closes with the noble gases of Group VIII, which are monatomic and essentially unreactive, a property that follows directly from their full outer electron shells.