How many atoms are in 165 g of calcium?

Moles in165g = 165 / 40 = N/6.02×10^23
N=2.48325×10^24
hope it helps

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

; lc