General Knowledge - Chemistry - Discussion

For example, let's take ammonia (NH3), which has one unshared pair.


If it is placed in an acidic solution (a proton donator), H+ ions (protons), the ammonia takes in the proton and becomes NH4+, an ammonium ion. The H+ ion has a vacant 1s orbital in its valence shell and can accomodate two electrons. The two unshared pair of electrons in the ammonia can be donated to the H+.


An arrow from the nitrogen atom to the hydrogen ion indicates that the nitrogen is sharing it pair of electrons with it. This sharing is called an coordinate covalent bond.

A coordinate covalent bond is one where both bonding electrons are from one of the atoms involved in the bond. These bonds give rise to Lewis acids and bases. The electrons are shared roughly equally between the atoms in contrast to ionic bonding.

Such bonding occurs in molecules such as the ammonium ion (NH4+) and are shown by an arrow pointing to the Lewis acid. Also known as non-polar covalent bond, the electronegativity of these bonds range from 0 to 0.3.

Nitrogen is not trivalent it's Pentavalent. But it uses its three electrons (of p-prbitals) for covalent bonding in NH3. And the fourth bond is Dative covalent formed by using of lone pair of N from (3s). After the formation of a coordinate covalent bond, it can also behave as a covalent bond due to having the same environment in ammonium ion. In this way, it forms 4 bonds.

Nitrogen belongs to the 15th group element so its valence is 3 and it reach the octet configuration gains 3 electrons from other atom or element. How is possible 4.

Covalent sigma bond is also called coordinate bond. So there is also possibility of nitrogen to form 4 covalent bond. We can say nitrogen having 4 covalent bond.

This question have more than one correct answer. Commonly 3 is right answer but when you give big exam as iit, ias etc. Then 4 is correct answer due to =N+=.

The valency of nitrogen is 3 that means its electron affinity is 3, so it can form 3 covalent bonds with other element then how it is 4 ?

N can form only 3 covalent bonds and the 4th bond that it forms is the co-ordinate covalent bond not covalent. So the right answer is 3.

N can form 3 covalent bond, e.g. NH3 and 1 co-ordinate covalent bond e.g. NH4+, which is a type of covalent bond. So the answer is D.

The covalency of nitrogen is 4 i.e.it forms 3 normal covalent bonds and a co-ordinate covalent bond.