The valency of chlorine, sulphur, and magnesium can be found based on their electronic configurations and how they achieve a stable octet configuration.
- Chlorine has an atomic number of 17 with electronic configuration 2,8,72,8,72,8,7. It has 7 valence electrons, so it gains 1 electron to complete its octet. Hence, the valency of chlorine is 1.
- Sulphur has an atomic number of 16 with electronic configuration 2,8,62,8,62,8,6. It has 6 valence electrons, so it gains 2 electrons to complete its octet. Hence, the valency of sulphur is 2.
- Magnesium has an atomic number of 12 with electronic configuration 2,8,22,8,22,8,2. It has 2 valence electrons, so it loses 2 electrons to achieve a stable octet in the previous shell. Hence, the valency of magnesium is 2.
In summary:
- Valency of Chlorine = 1
- Valency of Sulphur = 2
- Valency of Magnesium = 2
This is determined by the number of electrons they gain or lose to complete their outermost shell to achieve a stable octet configuration.
