Question

How does bond order correspond to phase? Use the drawing of MO energy diagram to predict the bond order of [Be2]+ and [Be2]−. Determined that the bond order of [Be2]+ is (+1/2).

Answer 1

Bond order is less in solid phases (usually 1), intermediate in liquid (2 or 3), and greatest in gases (3). [Be2]+ has a bond order of 1/2 and for [Be2]-, it has a bond order of 0. The bond order for [Be2]+ is calculated by:
(4 bonding e- - 3 nonbonding e-) / 2 = 1/2