Draw the mechanism of pyruvate dehydrogenase beginning with pyruvate, lipoamide, NAD and TPP in the ylid form, draw the mechanism of the formation of Acetyl CoA. Draw the structure of any relevant intermediates. You m

It’s the energy source of stars

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.