Electronic configuration of an element is . It is — Atomic Structure Chemistry Question

💡 Solution & Explanation

The atomic number corresponds to 5 electrons, which is Boron (B). The ground state of B is $1s^2 2s^2 2p^1$. The given configuration $1s^2 2s^1 2p^2$ has an electron promoted from 2s to 2p, making it an excited state configuration of B. Therefore, correct answer is B.