The atomicity of FeCO3 is
The atomicity of a molecule is the number of atoms present in it.
FeCO3 has 1 Iron (Fe) atom, 1 Carbon atom and 3 Oxygen atoms. So total of 5 atoms are present.
The atomicity is 5.
What should be the charge on CO3 in FeCO3 if the valency of iron is 2?