Answer:
Br⁻, Be²⁺, Li⁺ , O²⁻, N³⁻
Explanation:
Ions are formed when an atom lose or gain the electrons.
There are two types of ions.
Cations and anions
Cations:
When an atom lose the electron cations are formed and atom gain positive charge.
X → X⁺ + 1e⁻
Anion:
When an atom gain electron anion is formed and atom gain negative charge,
X + 1e⁻ → X⁻
In given list of elements Li and Be form positive ions because they easily lose their valance electrons.
Li → Li⁺ + 1e⁻
Be → Be²⁺ + 2e⁻
While oxygen, nitrogen and bromine gain the electrons easily to complete the octet and form negative ions.
Br + 1e⁻ → Br⁻
O + 2e⁻ → O²⁻
N + 3e⁻ → N³⁻
