Fluorine
Always -1
Hydrogen
+1 with nonmetals
-1 with metals
Oxygen
Usually -2 unless in a peroxide (then -1)
Group IA
Usually +1
Group IIA
Usually +2
Group VIIA
Usually -1
Group VI
Usually -2
Group VA
Usually -3
Atoms in elemental state
0
Atoms in monatomic ions
Equal to their charge