Ncert Exercises & Solutions

The electronic configuration of the element which is just above the element with atomic number 43 in the same group is ______.

1. $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{5} 4 s^{2}$

2. $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{5} 4 s^{3} 4 p^{6}$

3. $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{6} 4 s^{2}$

4. $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{7} 4 s^{2}$

Hint: Just substract 18 in atomic number 43 and find the next element which is just above the element with atomic number 43

The configuration of element which has 43 atomic number is as follows

$1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{10} 4 s^{2} 4 p^{6} 4 d^{5} 5 s^{2}$

The next element which is just above the element with atomic number 43 has atomic number 25.

The electtronic configuration is as follows:

$1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{5} 4 s^{2}$

Hence option 1 is correct.