The number of molecules in one mole of a substance The number of molecules in one mole of a substance depends on the molecular weight of the substance. depends on the temperature of the substance. depends on the atomic weight of the substance. is the same for all substances. depends on the density of the substance.

is the same for all substances.

Explanation:

The number of molecules in one mole of a substance is the same for all substances because

A mole (which is  the quantity of a substance that has the same number (Avogadro's number, is 6.022 * 10^23) of particles as are found in 12.000 grams of carbon-12 of the substance)  for any substance has  the same number of atoms, molecules, or ions contained in any other substance.

1 mole = 6.022 x 10^23 atoms, molecules, or ions

it means there are 3 atoms of oxygen

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a