How will you find the valency of chlorine, sulphur and magnesium

Explanation:

ANSWER

If the number of electrons in the outermost shell of an atom of an element is less than or equal to 4, then the valency of an element is equal to the number of electrons in the outermost shell.  

If it is greater than 4 then, the valance is determined by subtracting the outermost shell of electrons from 8.

The electrons in Cl, S, and Mg are 2,8,7 ; 2,8,6 ; 2,8,2  

Hence the valency of Cl, S, and Mg are 1, 2, 2 respectively.

Chlorine has 7 valence electrons

Magnesium has 2 valence electrons

Sulphur has 6 Valence electrons

Explanation:

We can find how many valence electrons by looking at the periodic table. For instance chlorine is a halogen and therefore has 7 valence electrons as it is in group 17. Magnesium is in group 2 so therefore has 2 valence electrons.

Sulphur is in group 16 and therefore has 6 valence electrons.

If the group has double digits I.e 16 like sulphur we only look at the second digit i.e. 6 as we can't have more than 8 valence electrons.

they deliver oxygen to the blood