Question

How many electrons does it take to fill

1. the MOs formed from combination of the 2p orbitals of two atoms;
2. a${\mathbf{\sigma }}_{2p}^{\ast }$ MO;
3. The MO’s formed from combination of the 2s orbitals of two atoms?

Short answer

Electrons in bonding orbitals stabilize they are between the nuclei

1. It takes four-electron to fill the molecular orbital, two from each 2p atomic orbital.
2. It takes two electrons to form a sigma anti-bonding molecular orbital.
3. It takes 4 electrons to form the molecular orbital from the combination of the two 2s atomic orbitals.

Step-by-step solution

Bonding

Bonding may be defined as the force of attraction between two or more atoms to form a compound. The molecule can have the same atom and a different atom.

The bonding can be formed by sharing or completing giving the electron from one atom to another.

A molecular orbital may be defined as the orbital formed by the combination of the two atomic orbitals.

2p orbital combination

There is the formation of a 2p molecular orbital from two 2p atomic orbitals using four electrons, two electrons from each orbital respectively. The p-orbital has a dumb-bell shape and can form a bond by head-on-overlapping and side-ways-overlapping to form the molecular orbital.

2p Sigma anti-bonding orbital

The 2p sigma bond is formed by the head-on-overlappingwhich is the strong covalent bond. The anti-bonding orbital is formed when the last electron enters the sigma anti-bonding 2p orbital.

2s molecular orbital

The 2s molecular orbital is formed by the combination of the two electrons from each 2s atomic orbital. Four electrons are involvedin the molecular orbital with head-on-overlapping in the s-orbital. The molecular orbital can be a bonding molecular orbital or anti-bonding orbital.