Answer:
A. Barium oxide : BaO
B. Iron(II)nitrate : Fe(NO3)2
C. Magnesium Sulfide :MgS
Explanation:
A. Barium symbol is Ba and it is a divalent cation and oxide is also divalent anion hence the formula Bao.
B. Iron is in +2 state symbol is Fe+2
&nitrate is A Monovalent polyatomic anion and symbols is NO3-
Hence formula is Fe(NO3)2
C. Magnesium symbol is Mg and it is a divalent cation, Mg+2
And sulfide is also Bivalent anion S2-
Hence formula MgS.
