Two gases A and B have the same Relative Molecular Mass. What else will be similar for gases A and B? * they have the same boiling point
they have the same molecular size
they diffuse at the same rate
they react in the same way

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.

Dsolubility let me know if you have any other questions for chemistry

This is a solution, hope i could