Question
Chemistry Question on Chemical bonding and molecular structure
Which one of the following molecules is paramagnetic?
A
F2
B
B2
C
Li2
D
N2
Answer
B2
Explanation
Solution
Molecules in which unpaired electrons are present, are paramagnetic while that have absence of unpaired electrons, are diamagnetic.
F2(18)=σ1s2,σ∗1s2,σ2s2σ∗2s2,σ2pz2,
π2px2≈π2py2,π∗2px2≈π∗2py2
(No unpaired electron, so diamagnetic)
B2(10)=σ1s2,σ∗1s2σ2s2,σ∗2s2,π2px1≈π2py1
(Two unpaired electrons, paramagnetic)
Li2(6)=σ1s2,σ∗1s2,σ2s2
(No unpaired electrons, diamagnetic)
N2(14)=σ1s2,σ∗1s2,σ2s2,σ∗2s2,π2px2
≈π2py2,σ2pz2
(No unpaired electrons, diamagnetic)