You might look at the the theory of the bang. It wasn't until hundreds of thousands of years after it banged into existence that the universe expanded and cooled enough to allow atoms to form. If electons momentarily met with protons to form a helium nucleus they were quickly split apart by photons, which themselves were trapped in a process of continual collision with the free electrons. This meant that the photons could not travel very far in a straight line and scattered.
Heavier elements were not formed, as you say, in the first moments of the big-bang. See 'opaque universe'.
Given 14.5+ billion years, a moment is a pretty long time.