Some nuclear waste is stored about 600 meters
below the desert in New Mexico inside caverns dug
out of an ancient bed of rock salt. The land above
the storage site is owned by the federal
government. Why do you think this location was
chosen?

Abbreviated as mg-25.

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.

The net force is 100