What is the mass of frutose also known as fruit (c6h12o6) in a 1.40×10^2ml sample of glucose solution that has a concentration of a 1.23m?

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.