Question

In which at least one sigma-bond of np orbital is
present :-
(1)B2
(2) O2
(3) C2
(4) Li2​

Answer 1

Answer: 2 and 3

each of these options are being explained below.

Explanation:

First up we have oxygen a diatomic molecule which has 8+8 16 no of electrons. Now this will be filled in the molecular bonding orbitals given in the order of energy levels as explained in the given diagram.

This will be spread as sigma 2s sigma 2s* π2px π2py π2pz π2px* π2py* π2pz*

The one's denoted by * are de generate orbitals with higher energy

Now the electrons will be filled with pauli principal that electrons will be filled according to low to high energy levels and hubli principal, while maintaining the spin orientation as well.

Bonding with O2 will be as follows for molecular orbitals

σ1s2 σ∗1s2 σ2s2 σ∗2s2 π2pz2 π2py2 π∗2py2 π2px1 π∗2py1

For boron B2 there's 10 electrons

σ1s2 σ∗1s2 σ2s2 σ∗2s2 π2px1 π2py1

For lithium Li2

There are 6 electrons

σ1s2 σ∗1s2 σ2s2

For carbon C2 there are 12 electrons

σ1s2 σ∗1s2 σ2s2 σ∗2s2 π2px2 π2py2

Hence we see only oxygen and carbon have at least one sigma np bond

Answer 2

Answer:

acha hu .... tum btao..........