Question

We know that nascent hydrogen are very reactive then why don't they with themselves?

Answer 1

Nascent hydrogen is nothing but an atomic hydrogen. It is generated in situ for the reduction of the species. It is a reactive species. So whatever is present in the system it will react restricted with some conditions like reduction potential, reactivity of a substance. If a substance with more reactivity than hydrogen itself is present in the system then it will react with that substance otherwise it can react with other atomic hydrogen to form hydrogen molecule.