Pick out the incorrect statement for transition metals

Options

A. they have low melting and boiling points (or low enthalpies of atomization)
B. 5d-elements have higher energies than 3d or 4d-elements
C. Zr and Hf have almost identical atomic and ionic radii
D. thtey form interstitial compounds.

Answer

A

Explanation

a) Transition metals have high enthalpies of atmization, because they form strong metallic bonds, due to participation of `(n-1)` d-electrons along with ns-electrons in metallic bonding.
b) This is due to the greater reffective nuclear charge acting on outer valence electrons, because of weak shielding of nucleus by 4f-electrons.
c) The normal size in increase from Zr to Hf is almost exactly balanced by lanthanide contraction.
d) Because small size, atom of H, He, C, N occupy the vacant spaces in the crystal lattice of transition metal.