Our world is made up of 4 fundamental forces, which are:
- Weak Interaction
- Strong Force
Each of these forces serves a purpose, for example. Gravity is what holds the planets and stars and galaxies together.
In the Atomic world, there are two fundamental forces that bind atoms together, and they are the Electromagnetic Force & Strong Force.
Because every atom is made up of protons and electrons, as well as Neutrons but they have a neutral charge. Protons and Electrons however have positive and negative charges. Protons have a positive charge, and Electrons have a negative charge. And as we know a positive and negative charge with both attract one another.
The centre of an atom is actually positively charged so with neutrons and protons. This means that they will exert a positive charge on electrons, which means that electrons will swarm around the Nucleus of an atom.
Strong Force and this is how protons and neutrons are bound together. The strong force is what binds the Nucleus of an atom together i.e. Protons and Neutrons. The electromagnetic force couldn't possibly keep the nucleus of an atom together, because it is much too weak, and the protons would simply repel one another and fly, because they are all positively charged, and we know that two positively charged particles won't attract each other. So there needs to be a stronger force, and that just happens to be the Strong Force.
The Strong Force is a force which attracts protons to protons and neutrons to neutrons, and protons and neutrons to each other. This force has a very short range, and this is the reason why a nucleus is very very small. This force is also responsible for binding Quarks and Gluons into Protons and Neutrons.
So from this we now know that the Electromagnetic Force is what keeps the electrons held in and orbiting the nucleus. The Strong Force is what holds the Nucleus of an atom together