Question

Describe the theory associated with the radius of an atom as it (a) gains an electron (b) loses an electron

Answer 1

Atomic radii- the distance from the center of the nucleus to the outer most shell containing the electrons.

(a)  along a period in periodic table ,the atomic radii of the elements generally decrease from left to right because the nuclear charges gradually increases on addition of electron in shell.

So, are also getting attracted more and more towards nuclei.

(b) When an atom loses an electron, the number of electrons decreases by one while the nuclear charge remains the same.

Therefore, the interelectronic repulsions in the atom decrease.

So, the effective nuclear charge increases.

Therefore, the radius of the atom decreases.