Question

What is the electronic configuration of an element in the first excited state which is isoelectronic with O2

Answer 1

Hey there!
O has 8 electrons
O2 has 16 elecrons
Isoelectronic element to O2 is Sulphur with atomic no. 16 i. e it contains 16 elecrons

Electronic configuration of S in ground state:
1s^2 2S^2 2P^6 3S^2 3P^4

Electronic configuration of S in excited stage:
1S^2 2S^2 2p^6 3S^1 3p^5
Hope that helps you ✌️

Answer 2

Answer:

[Ne] 3s^2 3p^3 3d^1

Explanation:

As total number of electron in O2 is 18,the isoelectronic element will be sulphur, which contains 18 electrons in ground state with cofiguration

[Ne] 3s^2 3p^4

In first excited stste 1 electron from 3p orbital will enter into 3d orbital and the configuration will be

[Ne] 3s^2 3p^3 3d^1