Why is the lewis structure of H2S bent at an angle but not linear?

Question

Why is the lewis structure of H₂S bent at an angle but not linear? When I drew the lewis structure, I drew the two hydrogens at a an 180 degree angle with sulfur in the middle. How do I distinguish between what to do when it looks like both works?

Answer 1

Consider the S atom at the center of the molecule. It has six electrons in the valence shell. Two of those electrons are bonded with the two Hydrogens. That leaves four electrons (2 unbonded pairs) that are not bonded to anything. This means that there are 4 groups (2 unbonded pairs and 2 H bonds) around the S atom.

The four groups give a tetrahedral electron geometry. Since there are 2 lone pairs of electrons and 2 bonds, the resulting molecular geometry is bent.

When determining the geometry of a lewis diagram it is important to consider the unbonded electrons around the central atom as well at the bonded electrons.

Hope this helps,

David