What is an ion with a negative charge?

An ion with a negative charge is known as an 'ANION'.

Examples are ;- Cl^(-) , O^(2-) , N^(3-)

NB An ion with a positive charge is a 'CATION'.

Examples are ;- K^(+) , Mg^(2+) , Al^(3+).

Collectively, anions and cations are known as 'ions'.

NNB When an atom loses or gains electrons, to become a charged species, it is no longer an atom, but an ION.