Question

Condition for formation of a covalent bond:
[A] Atoms should have two or more electrons in their outermost shell.
[B] Atoms should have four or more electrons in their outermost shell.
[C] Atoms should have three or more electrons in their outermost shell.
[D] None of the above

Answer 1

HINT: To answer this, you must remember that the bond formed by the sharing of electrons between two atoms is a covalent bond. You should know the minimum number of electrons involved in the formation of a bond.

COMPLETE STEP BY STEP SOLUTION: To answer this, firstly let’s discuss what a covalent bond is and it types and then we can proceed to answer the question.
-We know that a bond that is formed by the sharing of electrons between two or more atoms is known as a covalent bond. This bond is formed by atoms which do not have their valence shells fulfilled. Covalent bonding takes place between similar atoms in order to complete their octet by mutual sharing of electrons and hence gaining stability. Now we will discuss the types of covalent bonds.
Generally, we come across three types of covalent bonds in chemistry. They are-
-Single bond, When two electrons are shared between a pair of atoms, it gives rise to a sigma bond between the atoms, the sigma bond thus formed is known as a single bond.
-Double bond, When there is a sharing of four electrons by the two atoms, it gives rise to one sigma bond and one pi-bond and thus results in the formation of a double bond.
-Triple bond, When there is a sharing of six electrons by the two atoms, it gives rise to one sigma bond and two pi-bonds and thus results in the formation of a triple bond. We can see from the above discussion that covalent bonds can be formed between atoms having two or more electrons in their outermost shell.

Therefore, the correct answer is option [A] atoms should have two or more electrons in their outermost shell.

NOTE: A covalent bond is formed only when formation of an ionic bond is impossible between the two atoms. There are other factors too that we need to consider to understand covalent bonding. The atoms should be in a specific arrangement which must allow overlapping between the orbitals in order to form a covalent bond. A sigma bond is stronger than a pi-bond and thus it is difficult to break a sigma bond. The bond formed by the overlapping of atomic orbitals along the axis is the sigma bond.