PLEASE HELP A vessel contains 1.50 L of a gas at sea level where the pressure is 1.00 atm. What will be the volume when the pressure is 0.840 atm.
A. 0.810 L
B. 1.20 L
C.1.59 L
D.1.79 L

Although the diagram is not shown, i know that the convection is heated by a the core.

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.