Large amounts of energy are required in order to join two atom's nuclei into a single nucleus and, in turn, create a new element. what is the name of the process where two nuclei join to create a new element?
a) combining
b) elementium
c) fission
d) fusion

A) combining because you need to combine all elements together

Exothermic,  physical change after it is already baked

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.