Alkali Metal - GCSE Chemistry Definition

Alkali metals are a group of chemical elements found in Group 1 of the periodic table, and they include lithium, sodium, potassium, rubidium, caesium, and francium. These metals are characterised by their soft texture, low density, and high reactivity, especially with water, where they form alkaline hydroxides.

Alkali metals have one electron in their outermost shell, which they readily lose to form positive ions with a +1 charge, making them highly reactive and never found in their pure form in nature. Their reactivity increases as you move down the group, from lithium, the least reactive, to francium, the most reactive. In GCSE Chemistry, understanding the properties and reactions of alkali metals is essential for exploring trends in the periodic table and the behaviour of elements.