Final answer:
The mass of one molecule of oxygen is 5.31 x 10^-23 g, calculated by dividing the molar mass of oxygen (32.00 g/mol) by Avogadro's number.
Step-by-step explanation:
The mass of one molecule of oxygen (O2) can be calculated by first understanding the molar mass of oxygen and then using Avogadro's number to find the mass of a single molecule. We know that the molar mass of oxygen is 32.00 g/mol (since one mole of O2 has two oxygen atoms and the atomic mass of oxygen is approximately 16 g/mol).
Avogadro's number tells us that one mole contains 6.022 × 1023 molecules, so to find the mass of one molecule, we divide the molar mass by Avogadro's number:
(32.00 g/mol) / (6.022 × 1023 molecules/mol) = 5.31 × 10-23 g/molecule
Therefore, the mass of one molecule of oxygen is 5.31 × 10-23 g, which corresponds to answer choice A.