Question

Question #26e09

Answer 1

I'll assume you are referring to the charges on the ions which they form.

Zinc has the electron structure `[Ar]4s^2`

This means the principal oxidation states are 0 and +2.
`Zn^(2+)` is quite stable in aqueous conditions.

Copper has the electron structure `[Ar]3d^(10)4s^1`. The principal oxidation states are 0, +1 and +2

In aqueous conditions copper(I) is relatively unstable and it undergoes disproportionation to copper(II):

`2Cu^(+)rarr Cu+Cu^(2+)`