Two electronic configuration of an element 'A' are given below.
(Symbols not real)
$1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{1}$
$1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{1}$
(a) Identify the correct electronic configuration.
(b) Write the period in which the element is present in the periodic table.
(c) Consider another element 'C' with sub-shell configuration $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{1}$ . In which among the atoms A and C, the attraction of the nucleus towards the outermost electron is more? Give reason.

Open in App

Solution

(a) The correct electronic configuration of element A is:
$1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{1}$
(b) Fourth period.
(c) The electronic configuration of element A is
$1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{1}$
The electronic configuration of element C is
$1 s^{2} 2 s^{2} 2 p^{6} 3 s^{1}$
From the electronic configuration of the elements A and C, the atomic size of A is greater than the atomic size of C. Hence, the distance between the outermost electron of element A and its nucleus is more than the distance between the outermost electron and nucleus of element C. As the atomic size increases, the effective nuclear attraction experienced by the outermost electron decreases. Therefore, among the atoms A and C, the attraction of the nucleus towards the outermost electron is greater in case of element C.

Suggest Corrections

Similar questions

Given below are some elements of the modern periodic table:

_{$4^{B e}, 9^{F e}, 14^{S i}, 19^{K}, 20^{C a}$}

(i)Select the element that has one electron in the outermost shell and write its electronic configuration.

(ii)Select two elements that belong to the same group. Give reason for you answer.

(iii) Select two elements that belong to the same period. Which one of the two has bigger atomic size?

13

E

4 s^{2}, 4 p^{1} .

E

A

1 s^{2} 2 s^{2} 2 p^{6} 3 s^{1}

B

1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{4}

A

B

1 s^{2}, 2 s^{2}, 2 p^{6}, 3 s^{2} 3 p^{3}

Join BYJU'S Learning Program