Which of the following statements are correct about Zn,Cd and Hg?
(I) they exhibit high enthalpies of atomisation as the d-subshell is full
(II) Zn and Cd do not show variable oxidation states while Hg shows +I and +II
(III) Compound of Zn,Cd and Hg are paramagnetic in nature
(IV) Zn,Cd and Hg are called soft metals.