Question: Why don't molecules like to react?

Ruth Patchett answered on 20 Jun 2016:

Some molecules like to react more than others, this depends on a lot of things but it is based on how well they share their electrons in a chemical bond.

For example So if we think about methane it is made of a carbon and four hydrogens (CH4) these atoms are all about equally good at holding onto electrons meaning they share electrons in their bonds pretty evenly and well.
Other atoms like carbon-chlorine, the chlorine is much better at holding on to the electrons, therefore it actually pulls some away from the carbon a little bit. This is called a “polar” bond (like a magnet’s poles). This means that one atom has a lot of electrons and is happy to share them with a new atom, and one atom doesn’t have many left, so will try and take them from another atom if it gets a chance.

This also depends a lot on what you are trying to react your molecule with!