Answer : The correct option is, (C) sharing two electrons by two atoms
Explanation :
Covalent bond : It is defined as the bond that is formed when sharing of electrons takes place between the atoms.
This is usually formed between two non-metals.
As we know that the chlorine is a non-metal and has 7 valence electrons.
A covalent bond is formed between the two chlorine atoms by the sharing of two electron.
Ionic bond : It is defined as the bond that is formed when electron gets transferred from one atom to another atom.
This is usually formed between metal and non-metals.
As we know that the sodium is an alkali metal and has one valence electron and chlorine is a non-metal and has 7 valence electrons.
When sodium atom donates an electron to a chlorine atom then it forms an ionic compound that is sodium chloride (NaCl).
Hence, the correct option is, (C) sharing two electrons by two atoms
