Question

ammonia is called a covalent compound . why​

Answer 1

Answer:

Ammonia is covalent molecule. But due to electronegativity difference between N and H, the shared pair of electrons are attracted by N atom, making the bond polar. As the structure of ammonia is trigonal pyramidal , all the three polar bonds makes the molecule polar. So it is a polar covalent molecule

Answer 2

Answer:

When one atom supplies both electrons in forming a two-electron bond, it is known as a dative covalent or coordinate bond. If two atoms contribute one electron each, it is known as a simple covalent bond.

In this case, the nitrogen atom has a lone pair of electrons that coordinates to the hydrogen cation, which has zero electrons, forming a covalent bond. The resultant bond is now indistinguishable from the other three nitrogen-hydrogen bonds. This is important. The difference between simple and dative covalent bonds is in how they are made, but after they are made, they are the same bond.

For example you can hypothetically form hydrogen in two ways, giving the same molecule

Dative covalent

H−+H+→H2

Simple covalent

H.+H.→H