1. O ₂ 2. N ₂ 3. C ₂ 4. Be ₂

Answer: 3. C ₂ Write the MO configuration for each molecule. C₂ (12 electrons): σ_1s²σ_1s^(*2)σ_2s²σ_2s^(*2)π_2p⁴ . The 2p electrons occupy only the two π orbitals, so the bonding is two π bonds with no net σ bond. N₂ : has σ_2p² too, so one σ and two π . O₂ : one σ and one π net. Be₂ : bond order zero, not formed. Answer: option (3).

Topic: Molecular orbital theory, bond order, bond length, bond energy· Chemical Bonding and Molecular Structure

Which of the following diatomic molecular species has only π bonds according to Molecular Orbital Theory ?

1. O\(_2\)

2. N\(_2\)

3. C\(_2\)

4. Be\(_2\)

Doubtly Asked 30 Oct 2026 NEET UG 2019 Practice test neet Save WhatsApp Report

1 answer

Best answer

Answer: 3. C\(_2\)

Write the MO configuration for each molecule.

\(\mathrm{C_2}\) (12 electrons): \(\sigma_{1s}^2\sigma_{1s}^{*2}\sigma_{2s}^2\sigma_{2s}^{*2}\pi_{2p}^4\). The 2p electrons occupy only the two \(\pi\) orbitals, so the bonding is two \(\pi\) bonds with no net \(\sigma\) bond.
\(\mathrm{N_2}\): has \(\sigma_{2p}^2\) too, so one \(\sigma\) and two \(\pi\).
\(\mathrm{O_2}\): one \(\sigma\) and one \(\pi\) net.
\(\mathrm{Be_2}\): bond order zero, not formed.

Answer: option (3).

Doubtly AI · 30 Oct 2026 AI-generated · not yet verified Report

Was this answer helpful?

Which of the following diatomic molecular species has only π bonds according to Molecular Orbital Theory ?

1 answer

Your answer