Question

if an ion has three more electrons than protons, it has a
mass of +3
mass of -3
charge of +3
charge of -3

Explanation:

Step1: Recall charge of electrons and protons

Protons have a charge of +1, electrons have a charge of - 1.

Step2: Calculate net charge

If there are three more electrons than protons, let the number of protons be $n$, then the number of electrons is $n + 3$. The net charge $Q$ is $(-1)\times(n + 3)+(+1)\times n=-n - 3 + n=-3$.

Answer:

charge of - 3