AIIMS 2013 Chemistry Question Paper for free online practice with solutions

Cu has lowest melting point because it has lowest enthalpy of atomisation (i.e., heat required to break the metal lattice to get free atoms) among the elements.
Ni>Fe>Cr>Cu
Enthalpy of atomisation (In KJ mol−1) : Ni=430,Fe=416, Cr=397,Cu=339