WAEC - Chemistry (2012 - No. 2)
Which of the following electron configurations represents that of an atom in its ground state?
1s 22s12p1
1s22s22p63s13p1
1s22s12p3
1s22s22p63s0
Explication
The ground state of an electron, the energy level it normally occupies, is the state of lowest energy for that electron.