Question

In the 3d series from Sc (z=21) to Zn (z=30), enthalpy of atomization of Zn is the lowest.

Answer 1

Hint:We can say that enthalpy of atomization is the amount of enthalpy change when we break the bond of compound and the component atoms are decreased to individual atoms. We can define the change in enthalpy, which accompanies the total separation of all atoms in a chemical substance, is known as the enthalpy of atomization. The extent of metallic bonding determines the enthalpy of atomization.

Complete step by step answer:We have to remember that weaker interatomic bonding less will be the enthalpy of atomization.
In the series, from scandium to zinc, all elements show one (or) more lone pair of electrons other than zinc. The outermost electronic configuration of zinc is $3{d^{10}}4{s^2}$ and from this we can see that there is no unpaired electron in the element.
We know that Zinc is a transition element that has the atomic number thirty and it belongs to 3d series. The enthalpy of atomization is dependent on the extensive metallic bonding that in turn depends on the number of lone pair electrons. Lone pairs of electrons are absent in zinc, the interatomic bonding of zinc is weak. Due to the weak interatomic bonding present in zinc, the element zinc has lowest enthalpy of atomization.

Note: Let us know that the enthalpy of atomization of an elemental solid is exactly similar as the enthalpy of sublimation for any elemental solid which turns to a monatomic gas upon evaporation. Transition metals are elements present in groups 3-12. The transition metals are also called the d-block elements. These elements are categorized by their partially occupied d subshells in the free elements or in their cations. The difference in the oxidation states of transition elements is because of incomplete filling of d orbitals in such a way that their oxidation states vary from each other by unity.