Oxygen and hydrogen are most likely to form what type of bond?

A hydrogen bond. Hydrogen bonds are formed by H with N, O, F

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.