A McDonald's Big Mac is reported to have 540 Calories. How much energy is that in kilojoules (kJ)? Show all of your work to receive credit

Ci think not

And a) oxygen i believe

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.