Respuesta :
Metals tend to readily lose electrons and form cations. Most of them react with atmospheric oxygen to form metal oxides. However, different metals have different reactivities towards oxygen (unreactive metals such as gold and platinum do not readily form oxides when exposed to air
For sodium
- Nucleus =11+
- Core electrons=10-
- Valence electrons=1-
For Magnesium
- Nucleus=12+
- Core electrons=10-
- Valence electrons=2-
For potassium
- Nucleus=19+
- Core electrons=18-
- Valence electrons=1-