Everything in the world, for example, people, books, stars, consists of atoms. To visualize how small this quantity is, let’s say that the page thickness of the book is 500,000 atoms.

In each such tiny atom there is a nucleus consisting of protons and neutrons bound together. Around the nucleus, electrons rotate in their orbits. They revolve around the core just like planets around the sun.

What are atoms made of?

Atoms, therefore, are composed of particles: protons, neutrons and electrons. These particles are held together by electromagnetic forces. Electromagnetic force is one of the four main forces acting in the universe. Negatively charged electrons are attracted to positively charged protons of the atomic nucleus. Therefore, the electrons rotate stably in their orbits. The same electromagnetic force makes lightning flash.

Another force is gravity. It attracts material objects to each other and is directly proportional to their masses. This force keeps the planets in orbits and makes the picture tear off the wall to fall to the floor. Gravity is more noticeable than electromagnetic, but the latter is much stronger. The electric forces of attraction and repulsion between charged particles in an atom are a huge number of times greater than the gravitational force between them.

Forces of intranuclear interaction

In the nucleus of an atom there are forces called forces of intranuclear interaction. These forces compress the protons and neutrons of the atomic nucleus into a dense ball. The fourth type of force is the weak forces of intranuclear interaction. They are really very weak and become noticeable only in the process of radioactive decay of the nucleus upon the emission of elementary particles.

Interesting video