The atomic radius of Li, Na and K are 1: 33A, 1. 54A and 1. 96A res pectively. Which of the following explaqins this gradation in atomic radius?

Answer Details

The correct answer is "the number of the electron shells increases from Li to Na to K." This is because the atomic radius is determined by the number of electron shells an atom has. As you move down a group in the periodic table, the number of electron shells increases, resulting in a larger atomic radius. Since Li has the smallest atomic radius, it must have the fewest electron shells, while K has the largest atomic radius, meaning it has the most electron shells. Therefore, the correct explanation for the gradation in atomic radius from Li to Na to K is that the number of electron shells increases from Li to Na to K.