Anion - GCSE Chemistry Definition

An anion is a type of ion that carries a negative charge, meaning it has more electrons than protons. In the context of GCSE Chemistry, anions are formed when atoms or molecules gain one or more electrons.

This process typically occurs in reactions between metals and non-metals, where non-metal atoms gain electrons to achieve a full outer shell, resulting in a negative charge.

Anions are crucial in the formation of ionic compounds, as they pair with positively charged ions, known as cations, to create stable compounds.

Common examples of anions include:

• chloride (Cl^-)

• oxide (O^2-)

• sulfate (SO₄^2-) ions