Why do other elements react with one another?

Answer 1

In an atom of any element, their electrons are arranged in circles (or shells) around the central nucleus (where the protons and neutrons are.)

Atoms are very stable (non-reactive) when they have full outer shells of electrons - stable elements are called 'inert' e.g. Helium, Neon Argon etc.

Atoms 'want' to be stable, so they will easily react with any other element that will make them stable. During the reaction, electrons are either transferred from the atom of one element to another to make each stable, or they are shared between the atoms.

For example, salt (Sodium Chloride) is made up of one atom of Sodium and one atom of Chlorine. Sodium has one electron in its outer shell and Chlorine has 7 electrons. Both atoms need 8 electrons for a full outer shell.

So, Sodium donates its outer electron to Chlorine - Sodium now has no electrons in its outer shell, which makes it very stable. Chlorine gains the electron - it now has a full outer shell too so it is very stable.

The reason the sodium and the chlorine join together is that electrons have a negative charge. So when the electron is passed over, chlorine gets a negative charge and sodium gets a positive charge from losing the electron. They therefore attract each other, forming a bond.

Sodium Chlorine (salt) is so common because sodium and chlorine are so reactive and naturally bond together.

I hope this answers your question.