How many hydrogen atoms are in 1 molecule of C3H7O

How many grams are in 68.2 molecules of br2?

Which statement is actually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.

How much mass would a mole of hydrogen molecules contain? recall that hydrogen is diatomic. g/mol