Question

Na+,Li+,K+(In the order ofatomic size)

Answer 1

Answer:

As u haven't specified whether it is ascending order or descending order of the atomic size, let me give u both the answers.

Ascending order: $Li^{+}, Na^{+}, K^{+}$

Descending order: $K^{+}, Na^{+}, Li^{+}$

Explanation:

Always the number before the name of the shell indicates the period number and the number after the name of the shell tells us the group number.

In cases after s subshell some numbers have to be added to the number after the name of the shell to arrive at the group number.

In the modern periodic table made by the scientist Henry Moseley,

The atomic size increases down the group as new shells are added. Lithium electronic configuration: $1s^{2}, 2s^{1}$

Sodium electronic configuration- $1s^{2}, 2s^{2}, 2p^{6}, 3s^{1}$

Potassium electronic configuration- $1s^{2}, 2s^{2}, 2p^{6}, 3s^{2}, 3p^{6}, 4s^{1}$

Therefore Lithium belongs to the 2nd period and 1st group,

Sodium belongs to the 3rd period and 1st group

Potassium belongs to the 4th period and 1st group.

Hence we have this answer.

Hope this clears your doubts.