We are being asked to draw the MO energy diagram of Li_{2}^{+} and Li_{2}^{-} then predict which will exist in the gas phase.

**We will do the following steps**

*Step 1:* Calculate the total number of valence electrons present.

*Step 2:* Draw the molecular orbital diagram.

*Step 3:* Calculate the bond order of the molecule/ion. Recall that the formula for ** bond order** is:

$\overline{){\mathbf{Bond}}{\mathbf{}}{\mathbf{Order}}{\mathbf{}}{\mathbf{=}}{\mathbf{}}\frac{\mathbf{1}}{\mathbf{2}}\mathbf{[}\mathbf{\#}\mathbf{}\mathbf{of}\mathbf{}{\mathbf{e}}^{\mathbf{-}}\mathbf{}\mathbf{in}\mathbf{}\mathbf{bonding}\mathbf{}\mathbf{MO}\mathbf{}\mathbf{-}\mathbf{}\mathbf{\#}\mathbf{}\mathbf{of}\mathbf{}{\mathbf{e}}^{\mathbf{-}}\mathbf{}\mathbf{in}\mathbf{}\mathbf{antibonding}\mathbf{}\mathbf{MO}\mathbf{]}}$

**Part A**

Use the drawing of the MO energy diagram to predict the bond order of Li_{2}^{+}.

Express the bond order as an integer or fraction.

**Part B**

Use the drawing of the MO energy diagram to predict the bond order of Li_{2}.

Express the bond order as an integer or fraction.

**Part C**

Which molecules are predicted to exist in the gas phase?

A. Li_{2}^{}

B. Li_{2}^{+}

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the MO Theory: Bond Order concept. You can view video lessons to learn MO Theory: Bond Order. Or if you need more MO Theory: Bond Order practice, you can also practice MO Theory: Bond Order practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Ferguson's class at HAWAII.