How to Do Lewis Dot Structure (Simple)

The Lewis Dot Electron Diagram Explained

If you can figure out the number of valence electrons surrounding your atom, the construction of the Lewis dot forms is easy.   Here is a makeshift outline of the periodic table showing the number of valence electrons for each group of elements.  Don't laugh at my picture.

The elements in group 1A have one electron in their outer valence shells and the elements in group 7A have seven electrons in their valence shell.

(Elements in group 8A have eight electrons in their outer shells, but they are stable and non reactive because their outer shells are complete and happy with 8 electrons.  More HERE.)

So, let's choose the element Lithium in group 1A.  How many valence electrons does it have?

One.  Right?

To draw the Lewis Structure for Lithium, we must draw a dot representing its one valence electron around its chemical symbol.  It would look like this:

 That was easy.

Now how about Nitrogen?  Look at your periodic table.  Nitrogen is in group 5A, so how many valence electrons does it have?   Yep, Five.

We need to represent five electrons around the chemical symbol for Nitrogen, so its Lewis structure would look like this:

 The easiest way to place the electrons is to draw one dot at a time starting at the top going clockwise around the symbol.  Let's say that there are four "poles" (top, right, bottom, left).  For now there should never be more than two dots (electrons) at each pole.   And if there are two dots at a pole there should at least be one dot at the other poles. 

In other words, don't do this:

Make sure every pole has at least one electron before you go doubling up at the other ends.