It is considered that the primeval atom was, like everything primitive, the simplest: the hydrogen atom. Subsequent tests based on the quantification of the hydrogen isotopes in the universe, have shown that this assumption was correct and therefore we can give the character of the theory, under the name of nucleosynthesis theory that explains the production of all atoms mechanisms known elements by combining pressure and temperature, resulting from gravity in the center of stars, and expansion velocities resulting from the explosion of these stars.

The process can be explained by 9 steps that are presented here:

1. It is considered that free hydrogen atoms and primordial were grouped by gravity, forming an increasingly dense cloud, increasing the temperature and the number of collisions between hydrogen. Consequently atoms are split into electrons and nuclei, and a process of nuclear fusion is the fusion of two or more cores to result in a new heavier nucleus of a new element.

2. Every four hydrogen nuclei can generate a helium nucleus, two positrons, two neutrinos and release energy. The heavier helium nuclei accumulate in the center of the cloud and the whole acquires a spherical shape, it begins to shine, with the composite hydrogen resulting in a proto star surface.

3. Where the center of helium condenses and heats reaching 100 million degrees, the helium starts a merger giving rise to carbon nuclei and releasing more energy. At this time the proto star becomes a star with a helium nucleus, fusing a carbon surrounded by a layer of hydrogen fusing into helium. If the new star has a size comparable to the Sun the process stops at this point.

4. However, if the star has a size higher core temperature can reach 200 million degrees, the carbon nuclei begin a third merger and new heavier oxygen nuclei originate. If the star has a comparable size to a red giant, the process stops at this point.

5. If the star is equivalent to a red supergiant size (20 to 60 times a red giant) the process does not stop with the production of oxygen, and core temperature to reach 700 million degrees neon and magnesium melt originates, if it comes to 3 billion degrees melting silicon, sulfur, argon and calcium are produced and if reaches 5000 million degrees iron melting occurs. The red supergiant, the core is not capable of temperature and pressure to advance the fusion of new heavier than iron core nuclei. 

6. However with increasing iron concentration in the center of the red supergiant, it contracts and rising the temperature up to the melting point of the iron cores. But unlike other mergers, the merger of the iron cores not generate energy but absorbs energy and increases compression to cause the outbreak of the red supergiant resulting in a Supernova.

7. During the expansive explosion of a supernova such speeds cores violence of its shocks originate melt particles up to 60 more new elements heavier than iron are reached. It is considered that the percentage of gold and platinum produced during the explosion of a supernova are small. 

8. During the decomposition of the iron cores at the center of the red supergiant before the outbreak a lot of neutrons occurs once expelled eventually form neutron stars small (considered less than 10 km in diameter) but high density.

9. Finally, the collision of neutron stars, attracted by its high density, resulting in temperatures above 1 trillion degrees and formation of the nuclei of heavier elements existing in the universe.

Nucleogenesis these processes gives rise to all the known elements from hydrogen and after the explosions or collisions of stars, the materials are spread through the universe. Thus the formation of new stars and planetary systems starts.

However, the formation of solid planets can only occur if around a star of secondary type, like the sun, grouped remnants of cosmic dust are containing calcium, carbon, oxygen and silicon (main components of planetary crusts) besides the primordial hydrogen. These same elements by the nitrogen will also be the basis of vital biochemical processes as we know it on Earth.