Question

Which one of the following properties has same value for $H_2$ and $D_2$ ?

• A. density
• B. enthalpy of bond dissociation
• C. bond length
• D. melting point

Answer 1

Answer: (C)

bond length

Answer 2

Bond length depends upon the electrostatic force of attraction. Substituting a different isotope in the atom should not change the bond length. Since, the electrical environment around the isotope is identicle