fossils are ofter hardened remains of organaims that once loced. which characteristic of sedimentry rock makes it likely to be folssils found in this type of rock

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.

Bis the answerhope it !

Sorry i dont understand the question can you rephase it?