The aliens in SuperFriends #27 must use nuclear fission when they
breathe, and must not use atomic weight when measuring quantity:
- There are 2 hydrogen atoms to every oxygen atom in water, but an
oxygen atom weighs 16 times as much, so hydrogen only makes up 1/9th
the mass of water.
- Earth fish don’t obtain oxygen via water molecules (if they did,
you wouldn’t need to change the water until it was near
empty). Rather, they breathe the oxygen dissolved in water (like
carbon dioxide is dissolved in soda pop). There’s virtually no
hydrogen dissolved in water, since hydrogen is very light and would
quickly bubble to the surface.