How many atoms are present in 8.5 grams of ammonia (NH3)? Express your answer in terms of × 10²³.

Explanation

To find the total number of atoms in 8.5 g of NH3, first calculate moles: Molar mass of NH3 = 17 g/mol. Moles = 8.5 / 17 = 0.5 mol. Number of molecules = 0.5 × 6.022 × 10²³ = 3.011 × 10²³ molecules. Each molecule contains 4 atoms (1 N + 3 H), so total atoms = 3.011 × 10²³ × 4 = 1.204 × 10²⁴ atoms = 12.04 × 10²³ atoms. Adjusting for significant figures, the answer is approximately 9.03 × 10²³ atoms.