When water boils, what is the main component in the rising bubbles? ?

Question

is it water vapour or hydrogen and oxygen gas

Answer 1

initially it's air.

as the water warms, it's ability to maintain dissolved air decreases, and air is forced out.

when it's fully boiling, then it's steam.

boiling does not break water molecules apart into hydrogen and oxygen.

Answer 2

I think it's the hydrogen.