Based on their electrons dot diagrams, what is the formula for the covalently bonded compound of nitrogen and hydrogen?
The Correct Answer and Explanation is:
The formula for the covalently bonded compound of nitrogen and hydrogen is NH₃, which is known as ammonia.
Explanation:
To understand how we arrive at the formula NH₃, we need to examine the electron dot diagrams (Lewis structures) for nitrogen (N) and hydrogen (H).
- Electron Configuration:
- Nitrogen has an atomic number of 7, which means it has 7 electrons. Its electron configuration is 1s² 2s² 2p³. In the outer shell (the second shell), nitrogen has five valence electrons (two in the 2s subshell and three in the 2p subshell).
- Hydrogen, with an atomic number of 1, has one electron. Its electron configuration is simply 1s¹, meaning hydrogen has one valence electron.
- Covalent Bond Formation:
- Atoms bond covalently by sharing electrons to achieve a full outer shell, which follows the octet rule for most elements (except for hydrogen, which follows the duet rule).
- Nitrogen needs three additional electrons to complete its octet (8 electrons in its outer shell). Hydrogen, needing only two electrons, can bond with nitrogen to achieve a stable configuration.
- Bonding in Ammonia:
- In ammonia (NH₃), nitrogen forms three single covalent bonds with three hydrogen atoms. Each hydrogen shares its one electron with nitrogen, while nitrogen shares its three unpaired electrons with the three hydrogen atoms. This arrangement allows nitrogen to achieve a full octet and each hydrogen atom to achieve a stable duet.
- Lewis Structure Representation:
- The Lewis structure for NH₃ shows nitrogen in the center with three hydrogen atoms surrounding it, connected by single lines representing shared pairs of electrons. The nitrogen atom has a lone pair of electrons that are not involved in bonding, giving the molecule a trigonal pyramidal shape.
Thus, the compound formed between nitrogen and hydrogen is ammonia (NH₃), characterized by its covalent bonds and resulting molecular structure.