Hello!
From the list you gave, Mg (Magnesium) is the element that has two valence electrons
Why?
The valence electrons are the electrons that are found in the outer shell of the atom. That is, the shell with the highest "n" number.
From the list, the electron configuration of the atoms is:
- Na: [Ne] 3s¹. 1 Valence Electron.
- Mg: [Ne] 3s². 2 Valence Electrons.
- Al: [Ne] 3s² 3p¹. 3 Valence Electrons.
- S: [Ne] 3s² 3p⁴. 6 Valence Electrons.
The atom that has Two Valence Electrons from the list is Magnesium (Mg)
Have a nice day!
