Question

How many copper atoms are in a pure copper statue with a mass of 120 kg ?

Answer 1

There is 120000 grams in a pure copper statue.

Answer 2

Step #1: Convert to grams.

120kg × (1000g ÷ 1kg) = 120000g of copper

Step #2: Convert sample mass of copper to moles by dividing sample mass to its atomic weight. Atomic weights could be found in periodic table.

120000g Cu × (1mol Cu ÷ 63.55g Cu) = 1888.277mol Cu

Step #3: Convert moles to atoms by multiplying moles to Avogadro's number.

1888.277mol Cu × (6.022x10^23 ÷ 1mol Cu) = 1.137x10^27 atoms Cu

*I attached a picture to help out with conversions.