Eli5: How is hydrogen, a potent source of fuel with high energy release, combined with oxygen, a facilitator for combustion and energy release, mix together to make water which we drink like it’s no big deal?

Question

bonus points if you can explain why water has no caloric value, but hydrogen can power huge machinery.

In: 3

Answer 1

For the same reason that you can combine a deadly hundred-foot sinkhole with a treacherous 100-foot tower of stone to create flat ground that’s safe to walk on.

Even though the two have a lot of dangerous potential energy alone, together they are quite secure and relatively inert.