What is a chemical reaction and why do they occur?

What may be a simple question can have chemists discussing its definition in detail for days, and the reactions driving force can add even more complexity to it. But why do they occur?

In basic terms, a chemical reaction is an event where one or more molecules break and reform chemical bonds to end up in a different form than they started in.

However, to delve deeper into this idea we must know what causes chemical reactions to happen.

A chemical reaction favours one thing above all others, stability. Stability is expressed in chemistry through a value of the overall “randomness” of the product. The higher the value of different configurations that energy can be spread out in the product, the more stable a product is.