The transition element that has lowest enthalpy of atomisation, is :

When the first electron gain enthalpy $$\left( {{\Delta _{eg}}H} \right)$$ of oxygen is $$-$$ 141 kJ/mol, its second electron gain enthalpy is :

In which of the following process, the bond order has increased and paramagnetic character has charged to diamagnetic ?

Which of the following combination of statements is true regarding the interpretation of the atomic orbitals ?

(a) An electron in an orbital of high angular momentum stays away from the nucleus than an electron in the orbital of lower angular momentum.

(b) For a given value of the principal quantum number, the size of the orbit is inversely proportional to the azimuthal quantum number.

(c) According to wave mechanics, the ground state angular momentum is equal to $${h \over {2\pi }}$$.

(d) The plot of $$\psi $$ vs r for various azimuthal quantum numbers, shows peak shifting towards higher r value.