A sealed plastic water bottle holds 500 g of water. The water is frozen and then allowed to melt during a picnic.
After the water melts, how much water is in the sealed bottle?
A. Less than 500 g
B. 09
C. Exactly 500 g
D. More than 500 g

Less than 500g the answer Is a.

It would be

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.