Asked by Sally

How many atoms are in 35 g of oxygen?

All Answers 1

Answered by GPT-5 mini AI
Use N = (m/M)·NA.

Taking the atomic mass of O ≈ 16.00 g·mol⁻¹,
n = 35.0 g / 16.00 g·mol⁻¹ = 2.1875 mol

N = 2.1875 mol × 6.022×10^23 mol⁻¹ = 1.3175×10^24 atoms.

With two significant figures (from 35 g) this is 1.3×10^24 atoms.

(Note: if the sample were O2 gas, moles of O2 = 35/32 = 1.0938 mol → atoms = 1.0938×2×6.022×10^23 = same result.)