Question

How do polyatomic ions differ from monatomic ions?

Answer 1

By the number of atoms present in the ion.

Explanation:

Monoatomic ions are ions that consist of single atom . For example:
potassium ion, `K^"+"`
magnesium ion, `Mg^"2+"`
aluminum ion, `Al^"3+"`
nitride ion, `N^"3-"`
oxide ion, `O^"2-"`

Polyatomic ions are ions that consist of a cluster of atoms (more than one bonded to each other). For example:
ammonium ion, `NH_4^"+"`
carbonate ion, `CO_3^"2-"`
nitrate ion, `NO_3^"-"`
cyanide ion, `CN^"-"`