Answer:
4= Si
5=P
3= Al
6= S
2= Mg
Explanation:
4 → Si
Silicon is part of the carbon group and has 14 electrons, spread over 3 shells:
⇒ on the first shell (K) 2 electrons
⇒on the second shell (L) 8 electrons
⇒ on the third shell (M) the remaining electrons : 14-8-2 = 4
5 → P
phosphorus is part of the nitrogen group and has 15 electrons, spread over 3 shells:
⇒ on the first shell (K) 2 electrons
⇒on the second shell (L) 8 electrons
⇒ on the third shell (M) the remaining electrons : 15-8-2 = 5
3 → Al
Aluminium is part of the Boron group and has 13 electrons, spread over 3 shells:
⇒ on the first shell (K) 2 electrons
⇒on the second shell (L) 8 electrons
⇒ on the third shell (M) the remaining electrons : 13-8-2 = 3
6 → S
Sulfur is part of the oxygen group and has 16 electrons, spread over 3 shells:
⇒ on the first shell (K) 2 electrons
⇒on the second shell (L) 8 electrons
⇒ on the third shell (M) the remaining electrons : 16-8-2 = 6
2 → Mg
Magnesium is part of the Beryllium or alkaline earth metals group and has 12 electrons, spread over 3 shells:
⇒ on the first shell (K) 2 electrons
⇒on the second shell (L) 8 electrons
⇒ on the third shell (M) the remaining electrons : 12-8-2 = 2