In order to solve this one we have the information that 1 mol is equal to 6.022*10^23 molecules, then we need to find how many moles would be 5.3*10^28 molecules, we can do that by doing the following calculation:
6.022*10^23 = 1 mol
5.3*10^28 = x moles
6.022*10^23x = 5.3*10^28
x = 5.3*10^28/6.022*10^23
x = 88010.63 moles or in scientific notation = 8.80*10^4 moles