Which substance contains bonds that involved the transfer of electrons from one atom to another?

(1) CO2 (3) KBr

(2) NH3 (4) Cl2

The transfer of electrons is an ionic bond, therefore, we need to determine which substance includes an ionic bond.

CO2, is a covalent bond, which is the sharing of electrons, not transfer.

KBr, is an ionic bond, because (k) loses an electron to bromine.

So, our final answer is: - (3) KBr