Numford
Bond order

Bond order of Li₂

Bond order 1, diamagnetic. 6 electrons: Nb = 4, Na = 2.

LiLi
  • Li

Li₂Lithium

Bond order 1

6 electrons, all paired

i

Li2 exists in the vapour.

  • Bond order1
  • Magnetismdiamagnetic
  • Electrons6

Molecular orbitals

6 electrons
1bond order
diamagnetic

(Nb − Na) / 2 = (4 − 2) / 2

1s1s2s2sσ1sσ*1sσ2sσ*2sLi atomMoleculeLi atomEnergy

σ1s² σ*1s² σ2s²

Working

Bond order step by step

  1. Li₂ has 6 electrons: 3 from each Li.
  2. Up to N₂ (and its ions), the π2p pair lies below σ2pz and fills first.
  3. Configuration: σ1s² σ*1s² σ2s²
  4. Bonding electrons Nb = 4, antibonding electrons Na = 2.
  5. Bond order = (Nb − Na) / 2 = (4 − 2) / 2 = 1.
  6. Every electron is paired, so Li₂ is diamagnetic.

Class 11, Chapter 4 Chemical Bonding and Molecular Structure.

Questions

Bond order of Li2: quick answers

What is the bond order of Li2?

1. Bond order = (Nb − Na) / 2 = (4 − 2) / 2 = 1. Bonding electrons Nb = 4, antibonding electrons Na = 2.

Is Li2 paramagnetic or diamagnetic?

Diamagnetic. Every electron is paired, so Li₂ is diamagnetic.

What is the molecular orbital configuration of Li2?

σ1s² σ*1s² σ2s², with 6 electrons in all.

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