Here's a breakdown:

* Ion: An atom or molecule that has gained or lost one or more electrons, resulting in a net electrical charge.

* Monatomic: Meaning "one atom".

Examples of monatomic ions:

* Cations (positively charged):

* Sodium ion (Na⁺)

* Potassium ion (K⁺)

* Calcium ion (Ca²⁺)

* Aluminum ion (Al³⁺)

* Anions (negatively charged):

* Chloride ion (Cl⁻)

* Bromide ion (Br⁻)

* Oxide ion (O²⁻)

* Nitride ion (N³⁻)