How To Write Lewis Dot Structure For Ions And Show Their Formal Charges?

Write Lewis structures for these ions. Show all valence electrons and all formal charges.

(a) Amide ion, NH2- (b) Bicarbonate ion, HCO3- (c) Carbonate ion, CO3^2-


Lewis Dot Structure For Ions Guide

  1. Calculate the total number of valence electrons in a molecule (group number = number of valence electrons). If there is a positive charge, subtract from the total number of valence electrons. If there is a negative charge, add to the total number of valence electrons

  2. Draw our your molecule and put lines between atoms (bonds)

  3. Subtract electrons used in bonds (2 electrons per bond) from the total number of valence electrons

  4. Use the remaining electrons to make outer atoms happy (octet). Keep in mind hydrogen only wants 2 electrons

  5. If there are any electrons left, place them on the central atom.

  6. Check if everyone is happy(octet). If not use double and triple bonds.


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