In an atom there are levels of energy in the shell and sub shell
This energy level is expressed in the form of electron configurations.
Charging electrons in the sub shell uses the following sequence:
1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.
The electron configuration of the element silicon (Si): 1s² 2s² 2p⁶ 3s² 3p²
valence electrons Si = 4
The electron configuration of the element silicon (Si) +4⇒releases 4 electron: 1s² 2s² 2p⁶
valence electrons Si⁴⁺ = 8
The electron configuration of the element silicon (Si) -4⇒gain 4 electron: 1s² 2s² 2p⁶ 3s² 3p⁶
valence electrons Si⁴⁻ = 8
