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 is mostly in liquid form and oxygen is in solid form.
Hydrogen is present as single atoms and oxygen is bonded in compounds.

The right answer is B.

*Hydrogen is the most abundant element representing nearly three quarters of the mass of the universe.

*Hydrogen is found in the water that covers 70% of the surface of our planet as well as in all organic matter.

*Hydrogen is the simplest element in the universe. It is composed only of one proton (p) and only one electron (e-).

*Hydrogen is the lightest element of all elements and gases; it is 14 times lighter than air. A "spill" of hydrogen gas immediately diffuses into the air and pollutes neither the ground nor the water table.

*Hydrogen is invisible, odorless and nontoxic. It does not cause acid rain, does not deplete the ozone layer and does not generate dangerous emissions.