Why do we need formal charges?
1 Answer
Well, the modern concept of the chemical bond relies on the distribution of electrons between atoms....
Explanation:
Electrons can be transferred between species such that a cation, and an anion result....and the charged particles can bind electrostatically in an extended array to give a salt...
...and typically this interaction occurs between an electron-rich species, a metal, and an electron-poor species, a non-metal...
Alternatively, electrons can be shared to give covalent bonds, a region of high electron-density between two positively charged nuclei, such that internuclear repulsion is negated, and a net attractive force between the nuclei results...
In either case we utilize formal charges to keep track of the electrons..the which acts as the glue between the positively charged nuclear particles.
In either case, it is useful to introduce the concept of formal charge with respect to the ATOM, which may be altered by the loss or gain or electrons...and in every chemical reaction both mass and charge are conserved.