Question

Among the following, the configuration $1s^{2}2s^{2}2p^{5}3s^1$ is valid for the:

• A. Ground state of fluorine
• B. Excited state of fluorine
• C. Excited state of neon
• D. Excited state of sodium

Answer 1

The correct option is C Excited state of neon

The given configuration has total $10$ electrons and Neon also has $10$ electrons, with ground electronic configuration as $1s^{2}2s^{2}2p^6$.
If one eletron is excited from its outermost subshell i.e $2p$ to next subshell i.e. $3s$. The electronic configuration of excited state of Neon will be $1s^{2}2s^{2}2p^{5}3s^1$.