What does the subscript 2 show in this chemical equation? h2o → 2h o
a. there are 2 oxygen atoms.
b. there are 2 hydrogen atoms.
c. there is half of a hydrogen atom.
d. there are 2 water molecules.

Harvey kept a balloon with a volume of 348 milliliters at 25.0˚c inside a freezer for a night.  when he took it out, its new volume was 322 milliliters, but its pressure was the same.  if the final temperature of the balloon is the same as the freezer’s, what is the temperature of the freezer? the temperature of the freezer is  kelvins.

Given sno2 + 2h2 - sn + 2h20 tin oxide reacts with hydrogen to produce tin and water. how many moles of sno2 are needed to produce 500.0 grams of sn?

Why are people not able to skip a dive to the deepest part of the ocean