Question

Two electrons of one atom A and two electrons of another atom B are utilised to form a compound AB. This is an example of?
A. Polar covalent bond
B. Nonpolar covalent bond
C. Polar bond
D. Dative bond

Answer 1

Hint: To find out the type of bond. A bond is formed between the atoms when the electrons are shared between them. There are many types of bond formed between the atoms. After knowing the type of bonds, we are able to choose the correct option.

Complete Step by Step Solution:
Given that two electrons of one atom A and two electrons of another atom B are utilised to form a compound AB. .First we must know about the bonds:
Polar bond: It is a type of bond that exists between the atoms and electrons that are shared but they are pulled more closely towards one of the atoms in the bond. For example: Ethanol is polar because the oxygen atoms attract electrons because of their higher electronegativity than other atoms in the molecule.

Non- Polar Covalent Bond: It is a type of chemical bond that is made when electrons are shared equally. For example: ${{N}_{2}}$ gas where $N-N$ have the same electronegativity.

Polar covalent bond: When atoms are shared unequally in a covalent bond then polar covalent bond is formed. For example: Water ${{H}_{2}}O$ is a polar bonded molecule. The electronegativity value of oxygen is 3.44, while the electronegativity of hydrogen is 2.20.

Dative bond: When both electrons come from the same atom then dative bond is formed. For example: When the ammonium $N{{H}^{+}}_{4}$ ion is formed, fourth hydrogen is attached with the help of dative Covalent bond because only the hydrogen is transferred from chlorine to nitrogen.

As the atoms are shared equally to form the compound AB it is an example of covalent bond. This covalent bond may be polar or non- polar depending upon the electronegativity difference. So it is an example of polar covalent bond.
Hence, the correct answer is option (A).

Note: Students must know the difference between the types of bonds to answer these types of questions. Atoms are shared equally in covalent bonds but whether it is polar or nonpolar depends on their electronegativity.