AP Chemistrymediummcq1 pt
How many atoms are in 9.0 g of water (molar mass 18.0 g/mol)?
A.9.0 × 10²³ atoms
B.3.0 × 10²³ atoms
C.1.5 × 10²³ atoms
D.6.0 × 10²³ atoms
Explanation
Core Concept
9.0 g ÷ 18.0 g/mol = 0.50 mol H₂O, each with 3 atoms, so 1.5 mol of atoms × 6.02 × 10²³ = 9.0 × 10²³ atoms. Remember to multiply by atoms per molecule.
Correct Answer
A9.0 × 10²³ atoms
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