Of the following electron configurations of neutral atoms, which represents an atom in an
excited state?
A 1s2 2s2 2p5
B 1s2 2s2 2p5 3s2
C 1s2 2s2 2p6 3s1
D 1s2 2s2 2p6 3s2 3p2
E 1s2 2s2 2p6 3s2 3p

Quote from: Ansam on September 20, 2022, 01:00:47 PM
Of the following electron configurations of neutral atoms, which represents an atom in an
excited state?
A 1s2 2s2 2p5
B 1s2 2s2 2p5 3s2
C 1s2 2s2 2p6 3s1
D 1s2 2s2 2p6 3s2 3p2
E 1s2 2s2 2p6 3s2 3p

Electron in higher energy level then its normal or ground state.
Like in case of carbon its ground state is 1s2 2s2 2p2
and excited state is  1s2 2s1 2p3
In the given options all are regular ground  electronic configurations except B where the electron should be in 2p rather than 3s .