How many atoms of ca-46 would be found in a 25.0 g sample of naturally occurring calcium?

The number of ca-46 atoms found in 25.0 g sample is calculated as follows

find the moles of Ca = 25/46 = 0.543 moles

by use of Avogadro law

1 mole = 6.02 x10^23 atoms what about 0.543 moles

= 0.543moles/1mole x (6.02x10^23) atoms = 3.27 x10 ^23 atoms