(b) If you combine two atomic orbitals on one atom to make a new orbital, is this a hybrid orbital or a molecular orbital?

Consider the H₂⁺ ion. (a) Sketch the molecular orbitals of the ion and draw its energy-level diagram.

Consider the H₂⁺ ion. (b) How many electrons are there in the H₂⁺ ion?

Consider the H₂⁺ ion. (c) Write the electron configuration of the ion in terms of its MOs. (d) What is the bond order in H₂⁺?

Consider the H₂⁺ ion. (e) Suppose that the ion is excited by light so that an electron moves from a lower-energy to a higher-energy MO. Would you expect the excited-state H₂⁺ ion to be stable or to fall apart?

Consider the H₂⁺ ion. (f) Which of the following statements about part (e) is correct: (i) The light excites an electron from a bonding orbital to an antibonding orbital, (ii) The light excites an electron from an antibonding orbital to a bonding orbital, or (iii) In the excited state there are more bonding electrons than antibonding electrons?

(c) Calculate the bond order in H2-.

Draw a picture that shows all three 2p orbitals on one atom and all three 2p orbitals on another atom. (a) Imagine the atoms coming close together to bond. How many σ bonds can the two sets of 2p orbitals make with each other?

Draw a picture that shows all three 2p orbitals on one atom and all three 2p orbitals on another atom. (b) How many p bonds can the two sets of 2p orbitals make with each other?

Draw a picture that shows all three 2p orbitals on one atom and all three 2p orbitals on another atom. (c) How many antibonding orbitals, and of what type can be made from the two sets of 2p orbitals?

Indicate whether each statement is true or false. (a) p orbitals can only make σ or σ* molecular orbitals.

Indicate whether each statement is true or false. (b) The probability is always 0% for finding an electron in an antibonding orbital.

Indicate whether each statement is true or false. (c) Molecules containing electrons that occupy antibonding orbitals must be unstable.

Indicate whether each statement is true or false. (d) Electrons cannot occupy a nonbonding orbital.

Using Figures 9.35 and 9.43 as guides, draw the molecular orbital electron configuration for (d) Ne22 +. In each case indicate whether the addition of an electron to the ion would increase or decrease the bond order of the species.

If we assume that the energy-level diagrams for homonuclear diatomic molecules shown in Figure 9.43 can be applied to heteronuclear diatomic molecules and ions, predict the bond order and magnetic behavior of (b) NO+.

If we assume that the energy-level diagrams for homonuclear diatomic molecules shown in Figure 9.43 can be applied to heteronuclear diatomic molecules and ions, predict the bond order and magnetic behavior of (d) ClF.

Determine the electron configurations for CN+, CN, and CN-. (a) Which species has the strongest C¬N bond?

Determine the electron configurations for CN+, CN, and CN-. (b) Which species, if any, has unpaired electrons?

(a) The nitric oxide molecule, NO, readily loses one electron to form the NO⁺ ion. Which of the following is the best explanation of why this happens: (i) Oxygen is more electronegative than nitrogen, (ii) The highest energy electron in NO lies in a π_2p* molecular orbital, or (iii) The π_2p* MO in NO is completely filled.

(c) With what neutral homonuclear diatomic molecules are the NO⁺ and NO^- ions isoelectronic (same number of electrons)? With what neutral homonuclear diatomic molecule is the NO^- ion isoelectronic (same number of electrons)?

Consider the molecular orbitals of the P2 molecule. Assume that the MOs of diatomics from the third row of the periodic table are analogous to those from the second row. (a) Which valence atomic orbitals of P are used to construct the MOs of P2?

Consider the molecular orbitals of the P2 molecule. Assume that the MOs of diatomics from the third row of the periodic table are analogous to those from the second row. (c) For the P2 molecule, how many electrons occupy the MO in the figure?

The iodine bromide molecule, IBr, is an interhalogen compound. Assume that the molecular orbitals of IBr are analogous to the homonuclear diatomic molecule F2. (a) Which valence atomic orbitals of I and of Br are used to construct the MOs of IBr?

The iodine bromide molecule, IBr, is an interhalogen compound. Assume that the molecular orbitals of IBr are analogous to the homonuclear diatomic molecule F2. (c) One of the valence MOs of IBr is sketched here. Why are the atomic orbital contributions to this MO different in size?