Answer:
The element is oxygen.
1s² 2s² 2p⁴
Step-by-step explanation:
Let's consider the electron configuration of the excited state.
1s² 2s² 2p³ 3s¹
According to the Aufbau principle, the electron in 3s should occupy the shell with lower energy. The ground-state electron configuration is:
1s² 2s² 2p⁴
The differential electron is in the level 2. Then, the element is in the period 2.
The electrons in the last level are 2 + 4 = 6. Then, the element is in the group VIA or 16.
The element is oxygen.