The answer I'm pretty sure is a because it can't be d because ionic binding the electrons are affected and it can't be c because that's covalent bonding and it can't be b because they don't swap electrons.
Hydrogen bond is found between water molecule if im correct
Answer:
[Ar]3d4 is the ground-state electron configuration for the Mn4 ion
but i don't know whether it is paramagnetic or daimagnetic
According to IUPAC nomenclature the cation is named first followed by name of anion
in the given compound the cation is calcium (Ca^+2)
The anion is sulphide (S^-2)
So the name of the given compound will be Calcium shulphide