Question

How will you differentiate between the lone pair and a bond pair of electrons?

Answer 1

Every elements have electrons in their atoms. These electrons are in shells that are located outside the nucleus. One shell can have one or more orbitals. The orbitals that are closest to the nucleus are s, p and d orbital. An orbital can be divided into several sub-orbitals. One sub-orbital can hold a maximum of two electrons. When there are no electrons, it is called an empty orbital. When there is one electron in a sub-orbital, it is called an unpaired electron. When the sub-orbital is filled with a maximum of two electrons, it is called an electron pair. The electron pairs can be found in two types as bond pair and lone pair. The main difference between bond pair and lone pair is that bond pair is composed of two electrons that are in a bond whereas lone pair is composed of two electrons that are not in a bond.

Answer 2

The lone pair electrons do not involve in bond formations. For example, ${ NH }_{ 3 }$has "lone pair of electrons" in the central nitrogen atom. The central nitrogen atom contains "five electrons" in its outer most shell but only three electrons formed bond with hydrogen atoms and two electrons are left. This two electrons or a pair of electrons which does not takes place in "bond formation" is called lone pair electrons. Other three electrons which takes place in bond formation is called bond pair electrons.