The only positive ion found in h2so4(aq) is the
(1) ammonium ion (3) hydroxide ion
(2) hydronium ion (4) sulfate ion

There are no ions in a solution made of molecules.

A. volume stays constant. just took took the quiz

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.