Question

How many gold atoms are in an 0.333 ounce, 18 k gold bracelet? (18 k gold is 75% gold by mass.)?

Answer 1

0.333 ounce * 0.75 * 28.35 grams/ounce = 7.080 grams gold 7.080 grams Au / 196.967g/mol Au = 0.0359 mol Au 0.0359 mol Au * (6.023 * 10^23) atoms/mol = 2.24 * 10^22 Atoms Au