Question

One isotope of a metallic element has a mass number $65$ and $35$ neutrons in the nucleus. The cation derived from the isotope has 28 electrons. What is the charge of this cation?

Answer 1

No of proton $=65-35=30$
So, it contains the same number of electrons but here as it contains only 28 electrons, it means it is in the form of cation here.
So, cation is ${}_{30}^{65}{\text{M}}^{2+}$

The no. of charge on the cation is $2$.