1. Find the molar mass of oxygen (O2):
* Oxygen has an atomic mass of approximately 16 g/mol.
* Since oxygen exists as a diatomic molecule (O2), the molar mass is 2 * 16 g/mol = 32 g/mol.
2. Calculate the number of moles of oxygen:
* Moles = mass / molar mass
* Moles = 4 g / 32 g/mol = 0.125 mol
3. Use Avogadro's number to find the number of molecules:
* Avogadro's number states that there are 6.022 x 10^23 molecules in one mole of any substance.
* Number of molecules = moles * Avogadro's number
* Number of molecules = 0.125 mol * 6.022 x 10^23 molecules/mol
* Number of molecules ≈ 7.53 x 10^22 molecules
Therefore, there are approximately 7.53 x 10^22 oxygen molecules in 4 grams of oxygen.
