The Big Bang theory is a widely accepted scientific explanation for the origins of the universe. According to this theory, the universe began as a hot, dense, and extremely small point known as a singularity. It was not a single atom, but rather a state of extremely high energy and temperature.
The singularity is thought to have contained all the matter, energy, space, and time that make up our universe. The Big Bang was not an explosion in space; instead, it marked the beginning of space and time itself. As the universe expanded and cooled down, it underwent rapid expansion known as cosmic inflation, followed by the formation of fundamental particles and the subsequent creation of atoms.
In the early stages of the universe's evolution, only fundamental particles like quarks and electrons existed. As the universe continued to cool, protons and neutrons formed, which eventually combined to form the first atomic nuclei. However, it took some time for the universe to cool down enough for these atomic nuclei to capture electrons and form stable atoms, primarily hydrogen and helium.
So, while the Big Bang did not originate from a single atom, it started from a singularity and gradually evolved into the diverse array of matter and energy we observe in the universe today.