Question

Define the following terms:
a) electron-deficient
(b) electron-precise
(c) electron rich compound.
Justify your answer with an example.

Answer 1

Hint: By the electron-deficient , we mean the species which have incomplete octet, by electron-precise, we mean those species which have complete octet and by electron-rich compounds, we mean compounds which consist of extra electrons. Now with the help of this, you can easily answer the given statement accordingly.

Complete step by step answer:
- First of all, let’s discuss what an atom is. An atom is the smallest particle of an element and it consists of a large solid mass in its center known as the nucleus of the atom.
- The nucleus of the atom consists of the positively charged particles i.e. the protons and the neutral particles known as the protons. Outside the nucleus are the negatively charged particles i.e. electrons which keep on revolving around the nucleus in fixed circular orbits.
Now considering the statement as;
a) Electron -deficient species are those substances or the compounds in which the central atom has incomplete octet in its valence shell to form the bonds.
Example: Boron trifluoride (i.e.$B{{F}_{3}}$) the central boron atom has six electrons in its valence shell and is thus, electron deficient.
b) Electron -precise species are those substances or the hydrides in which the central atom has a complete octet of 8 electrons in its valence shell.
Example: methane (i.e.$C{{H}_{4}}$) the central carbon atom has eight electrons in its valence shell and is thus, electron precise.
c) Electron -rich compounds are those substances or the compounds in which the central atom has excess electrons than that required for the bond formation and these extra electrons are present in the form of lone pair of electrons.
Example: Ammonia molecule (i.e.$N{{H}_{3}}$) the central nitrogen atom has five electrons in its valence shell , three of which are used in the bond formation and two extra electrons are present in the form of lone pair of electrons.

Note: Protons tells us about the atomic number of the atom i.e. Z and the sum total of the protons and the neutrons gives the mass number i.e. A of the atom and the number of electrons in an atom is always equal to the number of protons present inside the nucleus.