How many covalent bonds can each of the following atoms make

How many covalent bonds can each of the following atoms make?

Solution

Ans. A covalent bond is a chemical bond involving mutual sharing of two electrons between two atoms. The maximum number of covalent bonds that an atom can form is equal to the number of electrons to be accepted (or donated) to attain nearest noble gas configuration.

Alternatively, the maximum number of covalent bonds that an atom can form is usually equal to its valency.   

I. Carbon: Atomic number = 6   ; electronic configuration = 1s² 2s²2p²

            Valency of C = 4

            Or, No. of electrons required to attain nearest noble gas (Ne, atomic number = 10) configuration is equal to 4. [= Atomic no. of Ne- Atomic no. of C = 10 – 6 = 4].

Thus, carbon can form a maximum of 4 convent bonds.    

II. Hydrogen: Atomic number = 1          ; electronic configuration = 1s¹

            Valency of H = 1

            Or, No. of electrons required to attain He configuration = 1

Thus, H can form a maximum of 1 convent bonds.    

III. Oxygen: Atomic number = 8 ; electronic configuration = 1s² 2s²2p⁴

            Valency of O = 2

            Or, No. of electrons required to attain Ne configuration = 2

Thus, O can form a maximum of 2 convent bonds.    

IV. Nitrogen: Atomic number = 7          ; electronic configuration = 1s² 2s²2p³

            Valency of N = 3

            Or, No. of electrons required to attain Ne configuration = 3

Thus, N can form a maximum of 3 convent bonds.   

V. Fluorine: Atomic number = 9 ; electronic configuration = 1s² 2s²2p⁵

            Valency of F = 1

            Or, No. of electrons required to attain Ne configuration = 1

Thus, F can form a maximum of 1 convent bonds.