What is the origin of an atom?

The origin of atoms can be traced back to the Big Bang, which is the prevailing scientific theory for the origin of the universe. According to this theory, the universe began as a hot, dense state approximately 13.8 billion years ago and rapidly expanded, cooling and forming subatomic particles such as protons, neutrons, and electrons. These particles eventually combined to form atoms, which are the building blocks of matter. Over time, these atoms combined further to form molecules, stars, galaxies, and eventually the complex structures we see in the universe today.

The Big Bang