In which of the molecules: a) oxygen, b) water, c) nitrogen, d) ammonia (NH3)

In which of the molecules: a) oxygen, b) water, c) nitrogen, d) ammonia (NH3), the total electrons will be displaced to one of the atoms and why?

The bond through the formation of common electron pairs is called covalent. It is of two types:

1. Non-polar – between the atoms of the same element in a simple substance, for example, oxygen – O2, nitrogen – N2.

2. Polar – between atoms of different elements in a complex substance. In this case, the total electron pair is biased towards a more electronegative element.

General electron pairs will be displaced in the H2O molecule towards O, since it is more electronegative than H, and in the NH3 molecule – towards N, for the same reason.