Question

how many valence electrons are in zinc?

Answer 1

1) look at the atomic number, so zinc has 30; 30 e-
2) start pluging the e- in th electron configuration:
1s2 2s2 2p6 3s2 3p6 3d10 4s2
3) the most stable is 3d10; there 2e- extra Zn(+2)

Answer 2

Two. The 3d subshell is complete in zinc, so it tends to act more like a lazy Group 2A metal than a classic transition metal, for example it reacts vigorously with acid to form H2, forms the +2 cation easily and almost never any other. It does not react with water, however, and its oxide is amphoteric.