Question

Find the valency of chlorine, magnesium and sulphur.

Answer 1

Valency:

1. The combining capacity of the atom of an element with the atoms of other elements in order to acquire eight electrons in its outermost shell (or two electrons in the first shell) is known as valency.
2. Valency of metal is$=$Number of valence electrons.
3. Valency of non-metal is$=8-$Number of valence electrons.

Valency of Chlorine $\mathbf{\left(}\mathbf{Cl}\mathbf{\right)}$:

1. The atomic number of Chlorine is $17$ and it is a non-metal.
2. The electronic configuration of Chlorine is $(2,8,7)$. Thus, Chlorine has $7$ valence electrons.
3. Since it is a non-metal, $\mathrm{Valency}=8-7=1$.

Thus, the valency of Chlorine is $1$.

Valency of Magnesium $\mathbf{\left(}\mathbf{Mg}\mathbf{\right)}$:

1. The atomic number of Magnesium is $12$ and it is a metal.
2. The electronic configuration of Magnesium is $(2,8,2)$. Thus, Magnesium has $2$ valence electrons.
3. Since it is a metal, $\mathrm{Valency}=2$.

Thus, the valency of Magnesium is $2$.

Valency of Sulphur $\mathbf{\left(}\mathbf{S}\mathbf{\right)}$:

1. The atomic number of Sulphur is $16$ and it is a non-metal.
2. The electronic configuration of Sulphur is $(2,8,6)$. Thus, Sulphur has $6$ valence electrons.
3. Since it is a non-metal, $\mathrm{Valency}=8-6=2$.

Thus, the valency of Sulphur is $2$.

Thus,, the valency of Chlorine, Magnesium and Sulphur are $1$, $2$ abd $2$ respectively.