Question: how was an atom created?

Lewis Wright answered on 13 Mar 2017:

Atoms are groups of fundemental particles – that is, particles that cannot be broken down further.

An electron is a fundemental particle, but the protons and neutrons that make up a nueclus, and are what the electron orbits, are not.

Protons and neutrons are made from 3 quarks each, There are 6 types of quark, and a total of 17 fundemental particles (including the recently confirmed Higgs Boson at CERN!).

Quarks were formed 1×10^-12 seconds after the Big Bang, after the inflation of the universe, in a period called the Electroweak Epoch. At this point the universe is incredibly hot. Not so hot that quarks cannot exist, but too hot for them to join together.
As the universe continued to expanded it also continued to cool, and things like the fundamental forces started to separate.

One second after the Big Bang, the universe is continuing to cool, and the Photon Epoch begins. A few minutes into the Photon Epoch and matter beings to form, things like protons, neutrons and electrons. It will be 379,000 years before the universe is cool enough to let electrons combine with nuclei, which is when they officially become atoms.