Question

note: to answer some of the questions, it may help to reference a periodic table. when an atom of oxygen (o) forms an anion by gaining two electrons, what is the anion’s charge? 2– 1– 1+ 2+

Explanation:

Step1: Recall electron charge

An electron has a charge of $-1$.

Step2: Calculate charge after gaining electrons

Oxygen gains 2 electrons. So total charge change is $2\times(-1) = -2$. So the anion's charge is $2-$.

Answer:

A. $2-$