Answer: He and Cl2
Explanation:
London forces are displayed by substances that are nonpolar such as gas molecules and nonpolar covalent bonds. H2O and HCl all contain polar covalent bonds. Hydrogen is bonded to a highly electronegative atom hence these substances exhibit hydrogen bond.Cl2 is nonpolar, same applies to He. Cl2 is a formed by a homonuclear covalent bond hence both He and Cl2 contain only London forces.
