Answer:
It is CaSO4.2H2O
Explanation:
Calcium has a valence of 2 because it has only two valency electrons.
Sulphate ( SO4)^2- is a radical with a valence value of 2.
When Calcium combines with sulphate in bonding,
Formular ==> Ca2(SO4)2
But the 2 cancel out.
Overall formular==> CaSO4
For hydrated, ==> CaSO4.H2O
