Given by the name of these compounds, they are formed if one or more hydrogen atoms are substituted for halogens
X = Cl, Br, I, F
Endo is more in reactants and exo is more in products because in exothermic reactions heat is released
The answer is (1) CaCO3. The bond between C and O is covalent bond. And the bond between Ca2+ and CO3 2- ion is the ionic bond. So the compound CaCO3 satisfy this condition.