Question

A covalent bond is formed;
(A) Transfer of electrons
(B) Sharing of electrons by a single atom
(C) Sharing of electrons
(D) Repulsion of atom between two atoms

Answer 1

covalent bond is sharing of electrons pairs with atoms. These are also known as shared pairs, which are stable as they balance attractive and repulsive forces between atoms. Very small amount of electronegativity is the result of strong covalent bonds between the atoms

Complete step by step solution:
When there is sharing of paired electrons between atoms the bond formed is known as covalent bond. This bond forms when there is a difference between the electronegativities of the atom is very very small for the transfer of electrons to occur to form the ions. Covalent bonding also has many interactions; it includes $\;\sigma - bonding,\;$ $\;\pi - bonding,\;metal - to - metal{\text{ }}bonding,\;three - center{\text{ }}two - electron{\text{ }}bonds\;$ etc
Let us see few examples of covalent bonding,
Hydrogen molecules are formed by covalent bonding by sharing the two electrons. The higher the electronegativity between the two atoms lower will be the covalent bond .
Hence a covalent bond is formed by sharing of electrons.

Additional Information:
The word covalent bonding was first used by IRVING LANGMUIR in 1919. According to Lewis an atom forms this bond to attain a complete outer electron shell.
For example, Methane. By the octet rule, the carbon atom in methane shows a valence of four and therefore is surrounded by 8 electrons. Four from hydrogen bonded to it and four from the carbon itself. Each hydrogen has a valence of one and is bonded by 2 electrons. The numbers of electrons correspond to full shells in the quantum theory of the atom; the outer shell of a carbon atom is the n = 2 shell, which can hold eight electrons, whereas the outer (and only) shell of a hydrogen atom is the n = 1 shell, which can hold only two.

Note:
A covalent bond is a bond formed by sharing of paired electrons between two atoms having very small electronegativities between them. They are said to be stable as they balance both repulsive as well as attractive forces.