How many moles are in 2.8x10^10 particles of s?

1 mole of S -------------- 6,02.10²³ particles
x moles of S -------------  particles



particles

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.