https://cosmologyandspace.wordpress.com/tag/oxygen/ https://cosmologyandspace.wordpress.com/tag/oxygen/ answers your question. If you are trying to go back to

https://cosmologyandspace.wordpress.com/tag/oxygen/ https://cosmologyandspace.wordpress.com/tag/oxygen/ answers your question. If you are trying to go back to "why is there anything?", then the answer is "we don't know precisely, but we do know that if those things hadn't happened, we wouldn't be asking the question, so so we have no basis of knowing whether it's random, rare, or a near-certainty for a new universe."