give the oxidation number of the indicated atoms/ion. mg in mg²⁺

Answer:

D. +2

Explanation:

Step1: Recall oxidation number rule

Oxidation number of a monatomic ion is its charge.

Step2: Identify the ion's charge

The charge of $Mg^{2 + }$ is +2. So oxidation number of Mg in $Mg^{2+}$ is +2.