The question is explain how each of the following change as you travel across the spectrum- wavelength, frequency and energy

The density would be 1.622

It shows that the experiment is designed properly.

Acovalent bond is formed between the two hydrogen bonds

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.