Chemguide: Support for CIE A level Chemistry
Learning outcome 3.7
There is really not much I can add to the syllabus statement. I can't possibly cover every possible dot-and-cross diagram you might come across in an exam.
The important thing is to do exactly what the question asks you. If it just asks for a dot-and-cross diagram, then you should show all the electrons, inner ones included.
If it asks for outer electrons only, then that is all you should draw.
And don't be tempted to use, say, red ink for one of the particles and black for the other one. You risk irritating the examiner - red is his or her colour.
And, of course, don't be worried if you have to draw more or less than 8 electrons in an energy level, or if you have a single electron somewhere in the outer level of something. It isn't uncommon. If you still believe that you have to have a magic 8 electrons, it is time you forgot that idea!
© Jim Clark 2019