Which contains the greatest number of moles of oxygen atoms?

B. OR C.

Explanation:

So, 1 mol of ethanol, C2H5OH contains 1 mol of atoms of O; 1 mol of formic acid, HCO2H contains 2 moles of atoms of O; and 1 mol of water, H2O contains 1 mol of atoms of O.

So, of the three compounds given, formic acid, HCO2H, contains the greatest number of moles of oxygen atoms.

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).