You need 1.00 liter of a buffer solution of ph 5.20 for use in the lab. what mass of the sodium salt of the conjugate base will be needed if 45.0 grams of the acid is used to prepare the solution

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.

Idon't see the pic?

The phase where ice changes directly to gas is called sublimation