We’re being asked to determine the bond order of B₂. For this, we need to 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:

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