FORMAL CHARGE Meaning and
Definition
-
Formal charge refers to a concept in chemistry that helps determine the distribution of electrons in a molecule or ion. It is used to determine the relative distribution of electron density and the location of charges within a molecule.
The formal charge of an atom within a molecule or ion is determined by comparing the number of valence electrons it should have (based on its position in the periodic table) with the number of valence electrons it actually has in the molecule or ion.
To calculate the formal charge of an atom, the following equation is used: Formal Charge = Valence Electrons - [Non-bonding Electrons + (1/2) Bonding Electrons]
Valence electrons are the electrons that an atom contributes to a molecule, whereas non-bonding electrons are the lone pair electrons that an atom possesses. Bonding electrons refer to the shared pair of electrons in covalent bonds between two atoms.
The sum of the formal charges of all atoms within a molecule should equal the overall charge of the molecule or ion. If the sum is zero, it indicates that the molecule or ion is neutral. If the sum is positive, it indicates an overall positive charge, and if the sum is negative, it indicates an overall negative charge.
Formal charges are useful in predicting the relative stability and reactivity of molecules and ions. They help understand the distribution of charges and electron density, as well as assist in studying resonance structures and determining the most stable arrangement of atoms.
Etymology of FORMAL CHARGE
The term "formal charge" originated from the field of chemistry. The word "formal" in this context comes from the Latin word "formalis", which translates to "relating to form". In chemistry, a formal charge is a concept used to describe the distribution of electrons in a molecule or an ion. It indicates the hypothetical charge that an atom would have if all the bonding electrons were shared equally between the bonded atoms. The use of the term "charge" refers to the electrical charge of an atom or ion resulting from the gain or loss of electrons.
