Valence electrons are those of an atom that can participate in the formation of chemical bonds with other atoms. They are important in determining how the atom reacts chemically with other atoms.
Lewis structures (also known as Lewis dot diagrams, electron dot diagrams, and electron dot structures) are diagrams that show the bonding between atoms of a molecule and the lone pairs of electrons that may exist in the molecule; allowing us to visualize valence electrons better. In the Lewis model, an element symbol is inside the valence electrons of the s and p subshells of the outer ring.
You can show either a single element or a molecule. The Lewis structure of carbon is shown in this figure, , the element symbol is inside of the valence electrons.
A Lewis structure can be drawn for any covalently bonded molecule, as well as coordination compounds. They are similar to electron dot diagrams in that the valence electrons in lone pairs are represented as dots, but they also contain lines to represent shared pairs in a chemical bond (pairs of dots can be used instead of lines; single, double, triple, etc.).
Lewis structures show each atom and its position in the structure of the molecule using its chemical symbol. Excess electrons that form lone pairs are represented as pairs of dots, and are placed next to the atoms.
The total number of electrons represented in a Lewis structure is equal to the sum of the numbers of valence electrons on each individual atom. Non-valence electrons are not represented in Lewis structures.