Q11.31P - Chemistry: Molecular Nature Of Matter And Change

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?

Step-by-Step Solution

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 1: 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.

 

Step 2: 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.

Step 3: 2p Sigma anti-bonding orbital

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

Step 4: 2s molecular orbital

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