Question

in a molecule of calcium sulfide, calcium has two valence electron bonds, and a sulfur atom has six valence electrons. How many lone pairs of electrons are present in the Lewis structure of calcium sulfide?

Answer 1

The answer is four, Ca has given up 2 electrons to sulfur with six which makes 8 e-, or 4 pairs.

Answer 2

Answer :  The number of lone pairs of electrons present in the Lewis-dot structure of calcium sulfide are, 4.

Explanation :

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

In the Lewis-dot structure the valance electrons are shown by 'dot'.

The given molecule is, $CaS$

As we know that calcium has '2' valence electrons and sulfur has '6' valence electron.

Therefore, the total number of valence electrons in $CaS$ = 2 + 6 = 8

According to Lewis-dot structure, there are 4 number of bonding electrons and 4 number of non-bonding electrons.

In order to attain stability, the calcium metal will donate its two extra electrons to the sulfur atom. Thus, the calcium sulfide is an ionic compound.

The Lewis-dot structure of $CaS$ is shown below.