Which molecule has a bond order of 1 and is diamagnetic?
For Li₂ : (sigma 1s)² (sigma^* 1s)² (sigma 2s)² . Bonding = 4, antibonding = 2. Bond order = (4 - 2/2) = 1 , with all electrons paired (diamagnetic).
Ref: NCERT Class 11 Chemistry > Chapter 4: Chemical Bonding and Molecular Structure > Topic: Molecular Orbital Theory - MOT and Bond Order and Magnetic Properties