Imagine you were assigned as the lawyer for Rubin Carter. You're going to target two pieces of evidence that were used against him. You will argue in his favor in court in
order to get him a "not-guilty" verdict.

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.

H2so4 is the chemical compound of sulfuric acid. 

The image seems to be behind the mirror, but nothing is really there. if someone looks behind the mirror, there is no image there.