what is the charge of a PHOSPITE ?

Question

and how do i write it?

Answer 1

phosphate = PO₄^-3

phosphite = PO_3</^-3

Here is a good site for all of the polyatomic ions, including phosphite ion.
(Broken Link Removed)

Answer 2

phosphite should be PO₃^-3

Answer 3

okay then, what is calcium phospite?

Answer 4

Ca3(PO3)3 in my book. However, to be fair about it, I looked on the web AND in The Merck Index and found CaHPO3 and it was labeled calcium phosphite. Technically, however, that should be called calcium hydrogen phosphite