Air Date: Week of If you combine hydrogen and oxygen in a fuel cell, you get water and clean, green electricity. Bruce Gellerman reports on how this chemical reaction is fueling visions of future, carbon free flights and changing voyages of fantasy into reality. Transcript DOERING: Ok Paloma, in honor of the start of the school year, you ready for a pop quiz? BELTRAN: [nervous laugh] oh-oh kay??... DOERING: How much do you remember from gen chem?