Question

In the sigma bond
A. Sidewise, as well as end-to-end overlapping of orbitals take place
B. Sidewise overlap of orbitals takes place
C. End-to-end overlap of orbitals takes place
D. None of the above

Answer 1

Hint: The overlap of orbitals is essential for the formation of covalent chemical bonds. It is defined as the combining of orbitals of adjacent atoms in the same parts of an area or space. This combination leads to the formation of a hybridised orbital.

Complete Step by Step Answer:
Partial linking or interpenetration of atomic orbitals is defined as overlapping due to which the pairing of electrons happens.
When two atoms become near to each other, the merging of orbitals to form a hybridized orbital encloses the bonding pair of electrons.
This stability of the hybridized orbital is due to its lower energy than the atomic orbital.
The magnitude of overlap decides the strength of a covalent bond.
Greater overlapping ensures higher stability of the covalent bond.
The covalent bond is categorised into two types relying on the overlap of orbitals.
Sigma bond
This is created by the end-to-end or head-on overlapping of bonding orbitals along the internuclear axis.
This is also known as head-on overlap or axial overlap.
In this case, a higher degree of overlapping happens.
So, it is a stronger bond than a pi-bond.
In the pi bond, the atomic orbitals coincide and their axes stay parallel to each other and perpendicular to the internuclear axis.
The orbitals constituted by side-wise overlapping have two saucer-type charge clouds above and below the plane of the bonded atoms.
Here we have been asked in the sigma bond which type of overlapping happens.
In a sigma bond, end-to-end overlapping happens.
So, option C is correct.

Note: Covalent bond is a chemical bond constituted by the sharing of electron pairs between atoms. These electron pairs are named shared pairs or bonding pairs. We know that single bonds comprise one sigma bond. Double bonds comprise one sigma and one pi-bond, and triple bonds have one sigma and two pi-bonds. Double bonds are less stable than a single bond due to their greater reactivity. This is because double bonds are electron rich and the weak pi-bond can be shared by another electron acceptor like halogens.