[ColdWater]

If you are talking about hydrogen combustion, it is not an E=MC2 reaction.

But it is.

[thackney]

No, burning hydrogen does not convert mass to energy.

The mass of the reactants will equal the products.

2H₂ + O₂ -> 2H₂O

There are equal amounts of each element on both sides of the equation.

A nuclear reaction is not the same.