Question

Assertion (A): Potassium has a bigger atomic radius than lithium. Reason (R) Atomic radius deceases along a period.​

Answer 1

Answer:

These electrons can also be accommodated in 3shells but there is only 1electron in the outermost shell. Lithium has an atomic number of 3. ... Because of the large atomic sells of Potassium, it's atomic radius is Much larger than that of Sodium or Lithium.

Answer 2

a) The potassium atom has an extra electron shell compared to the sodium atom, which means its valence electrons are further from the nucleus, giving potassium a larger atomic radius.

b) Atomic radius is the distance from the atom's nucleus to the outer edge of the electron cloud. In general, atomic radius decreases across a period and increases down a group. Across a period, effective nuclear charge increases as electron shielding remains constant.