What is the main difference between physical properties and chemical properties

Physical looks at appearance e.g if its solid 
chemical is more of what it contains and how it reacts e.g metals 

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.