SDN Members don't see this ad. (About Ads) I have this question and the answer explanation which does not seem to make any sense to me. Can anybody explain please? You would be my hero. "Given the order in which orbitals are filled, which one of these would be a triplet in its ground state?" answer choices: - H2, O2, N2, F2 Answer explanation: The answer to this question is found in the passage:You are given the order of orbital filling in paragraph three and are told in the last paragraph what a triplet state is. Remember that when there are orbitals of equal energy, each one will be half-filled before any of the orbitals is com- pletely filled, and all the half-filled orbitals will have electrons with the same spin. Looking at the answer choices for the question, you can see that they are all diatomic; thus, there will be two electrons in a hydrogen molecule, fourteen in nitrogen, sixteen in oxygen and eighteen in fluorine. The passage does not describe how to fill the n = 1 shell, but from knowing that the n = 2 shell has the sigma 2s bonding orbitals and one sigma 2s antibonding orbital, there will be sigma bonding and antibonding orbitals in the n = 1 shell, and these will also hold four electrons. Therefore, molecular hydrogen will fill half the n = 1 shell with the total of two electrons that it has and there will be zero electrons in its second shell. Working in a similar way you will have ten electrons in the second shell for molecular nitrogen, twelve for oxygen, and fourteen for fluorine. When you fill in the molecular orbitals, you will find that nitrogen just fills the pi 2x and 2y bonding orbitals. Since there are no unpaired electrons, molecular nitrogen cant be a triplet. Molecular oxygen has two extra electrons, which go into the pi 2x and 2y antibonding orbitals. In other words it has unpaired electrons with the same spin. If youre not sure, check the final choice: In fluorine, these pi 2x and 2y antibonding orbitals are filled with the two extra electrons, so fluorine is not a triplet. Thus, it turns out that the oxygen molecule is a triplet in its ground state, so choice B is the correct answer. The Triple State is considered you have 2 unpaired electrons in separate orbitals. The bolded is what I do not understand. I understand that when you fill up 1S and 2S, you'll have 4 electrons filled into the orbitals. But the 2p orbitals (x, y, and z) can only fill up 6 more, so I don't understand WHAT they mean when they say that you can JUST FILL IN 2x and 2y bonding orbitals of nitrogen. Thank you!