What is the percent yield of a reaction in which 121g of solid phosphorus trichloride reacts with excess water to form 80.7 g of hydrogen chloride gas and aqueous phosphorous acid, H3PO3?
Round molar masses and final answer to 3 significant figures

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.

Idont really know sorry

C, small, hard spheres with insignificant volumes