Question

there are more hydrogen atoms in living organisms than any other atom, but oxygen is more abundant in terms of mass. why is this statement true? hydrogen is a gas, but oxygen is a solid. hydrogen atoms have a lower mass than oxygen atoms. hydrogen atoms make up more of waters mass than oxygen atoms. hydrogen is present as single atoms and oxygen is bonded in compounds.

Explanation:

• Hydrogen atoms have a lower mass than oxygen atoms. In living organisms, although there are more hydrogen atoms, oxygen has a higher atomic mass. When calculating the mass - abundance (mass = number of atoms × atomic mass), even with fewer oxygen atoms, their higher atomic mass makes oxygen more abundant in terms of mass.
• For example, in water (\(H_2O\)), there are 2 hydrogen atoms and 1 oxygen atom. The atomic mass of hydrogen (\(H\)) is approximately \(1\space g/mol\) and that of oxygen (\(O\)) is approximately \(16\space g/mol\). In one mole of water (\(H_2O\)), the mass of hydrogen is \(2\times1 = 2\space g\) and the mass of oxygen is \(1\times16=16\space g\).

Answer:

Hydrogen atoms have a lower mass than oxygen atoms.