J.R. S. answered 10/15/17
Ph.D. in Biochemistry--University Professor--Chemistry Tutor
Since Zn can have only 1 valence of 2+, you need not use the Stock system of Roman numerals. Zn is, in fact, a transition metal, but it is one of the few that have only a single valence (Sc and Ag are other examples). So, the correct name for Zn(OH)2 is simply zinc hydroxide.