Answer:
2 × 10⁻²² g
Step-by-step explanation:
Step 1: Given data
Atoms of oxygen: 9 atoms
Step 2: Calculate the moles corresponding to 9 atoms of O
We will use Avogadro's number: there are 6.02 × 10²³ atoms of O in 1 mole of atoms of O.
9 atom × 1 mol/6.02 × 10²³ atom = 1 × 10⁻²³ mol
Step 3: Calculate the mass corresponding to 1 × 10⁻²³ moles of O
The molar mass of O is 16.00 g/mol.
1 × 10⁻²³ mol × 16.00 g/mol = 2 × 10⁻²² g