Question

gold sample contain 90% of

gold and the rest copper. how

many atoms of gold are present in one gram of this sample of

gold?

Answer 1

1g of gold has approximately 3.057 * 1021 atoms.

Answer 2

Given that Gold Sample Contains 90% of Gold and 10% Copper

⇒ 1 Gram of this Sample Contains 90% of Gold and 10% Copper

⇒ 1 Gram of this Sample Contains (90/100) grams of Gold

⇒ 1 Gram of this Sample Contains 0.9 grams of Gold

We know that 1 Mole of Gold weighs 197 grams

1 Mole of any Element Contains 6.023 × 10²³ atoms in it

⇒ 6.023 × 10²³ atoms of Gold weigh 197 grams

⇒ 0.9 Grams of Gold Contains : {0.9 × 6.023 × 10²³}/197 atoms

⇒ 0.9 Grams of Gold Contains : 2.75 × 10²¹ atoms

⇒ The Given Sample of One Gram contains : 2.75 × 10²¹ Gold atoms