Question

What is the correct order of covalent size of the following? Cu ____Zn
A.Cu > Zn
B.Cu < Zn
C.Cu = Zn
D.None of these

Answer 1

The distance between an atom's nucleus and its outermost shell is measured in atomic size. The atomic radius is known as the shortest distance between the nuclei of an atom and the atom's outermost shell in basic chemistry.

Complete answer: In a molecule, an atomic radius is half the distance between neighbouring atoms of the same substance. In fundamental chemistry, we can see a lot of patterns in the properties (physical and chemical) of elements as we move down a group or up a column or row in the current periodic table. For example, the reactivity of elements decreases as we move down a group of nonmetals, while it increases as we move down a group of representative metals.
As two atoms are united, the difference between them can be used to measure their atomic size. Another way to determine the atomic size of a non-metallic element is to create a single covalent bond between two atoms and calculate the distance between them. The covalent radii of the element are the radius found using this process. It's known as a metallic radius in the case of metal. Half of the total distance between the nuclei of two adjacent metal ions joined by a metallic bond is known as a metallic bond.
Since Zn has a $3{d^{10}}$ structure, while Cu has a $3{d^9}$ configuration, Zn has a larger covalent scale than Cu. As a result, as the number of d electrons increases, the screening effect increases, resulting in less nuclear attraction for the outer 4s orbital electrons, resulting in a smaller scale contraction. As a result of the less d electrons, Cu's effective nuclear charge would be higher. As a result, the screening effect is reduced, resulting in a higher effective nuclear charge and a smaller covalent radius than Zn.
Hence option B is correct.

Note:
In general, as we move from left to right in a time, the atomic radius decreases, whereas it increases as we move down a group. This is because the valence electrons in intervals are all in the same outermost shell. When going from left to right, the atomic number changes, resulting in an increase in the effective nuclear charge. The atomic radius of elements shrinks as enticing forces rise.