A student needs 15.0 g of ethanol for an experiment. If the density of enthanol is 0.789 g/mL, how many millilitres of ethanol are needed?

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.

Answer; carbon monoxide (co);

Contained in chromosomes which are located in the nucleus of the cell.