Explanation:
we can find number of atoms in a given sample by the formula :
Number of atoms = Given mass /atomic mass x Avogadro's number
or , it can be written as :
Number of atoms = given mass /atomic mass x 6.022 x 10²³
Now in above asked question , the values given are :
Mass of sample of gold = 72.04g
Atomic mass of gold : 196.6
Avogadro's number = 6.023 x 10²³
so, using the above formula we have :
Number of atoms = 72.04 /196.6 x 6.022 x 10²³
= 0.3664 x 6.022 x 10²³
=2.207 x 10²³ number of atoms
