Question

How many atoms are in 12.8 g of copper metal?

Answer 1

The first step to solve this question is to convert the given mass of copper to moles using its molecular mass (63.5g/mol):

`12.8g\cdot(1mol)/(63.5g)=0.2mol`

Now, use Avogadro's number to find the number of atoms in 0.2 moles. Remember that it states the number of atoms in 1 mole of substance is 6.022x10^23.

`0.2mol\cdot(6.022*10^(23)atoms)/(1mol)=1.2044*10^(23)atoms`

There are 1.2044x10^23 atoms of copper in 12.8g of copper metal.