Question

hydrogen fuel cells are a type of alternative energy. these cells are expensive, but they produce no air pollution. what is the major by - product of hydrogen fuel cells? water carbon dioxide

Explanation:

Hydrogen fuel cells work by combining hydrogen and oxygen. The chemical reaction \(2H_2 + O_2=2H_2O\) occurs. Since there is no carbon involved (unlike fossil - fuel combustion which produces \(CO_2\)), the major by - product is water. Carbon dioxide is not produced as there is no carbon in the reactants (hydrogen fuel cells use hydrogen, usually from electrolysis or reforming without carbon - containing products in an ideal, non - fossil - based hydrogen source).

Answer:

Water