Count the total number of atoms in the chemical formula 5H2O2

Which of the following is true for the actual yield of a reaction? it is always calculated as a ratio. it is the yield from the excess reactant. it is the yield from the limiting reactant. it is always less than the theoretical yield.

The climate of the continental united states is generally 1. tropical 2. temperate 3. arctic 4. highland

If 16.00g of hydrogen gas reacts with 126.73g of oxygen, how many grams of water are yielded? (both reactants are completely consumed in the reaction.)