3.Early creation of the universe.

There must be a start to the existence of the universe.You cannot say that the universe existed back to nowhen in time, back in the period when the time stay still. Perhaps it started from something like the big bang explosion of the primordial atom........... . Now, what is the history of the atom? Was it stable before the explosion. Was it stable for,say, trillions years before the explosion. How did the primordial atom existed?