How to draw a Bohr Rutherford ion diagram?

You just draw circles (shells) around the small nucleus.

f.e for the Lithium:

1) You draw a small dot - thats you nucleus

2) draw a circle around it - thats you first shell and fill it with 2 electrons.

3) now if it was not an ion, then you would again draw a circle around the first circle (that would have been your second shell) and draw the third electron but now since it is an ion and that electron is lost so you dont draw it.

4) so now you have 1 nucleus with a full first shell. Then you draw big parenthesis [ ] around it and write the ion of the element as a superscript. In this case it is +1.

So now you should get something like this:

[ O ]+1 , where O is your shell and the electrons.

So basically drawing an ion diagram is just the same as drawing a normal diagram, but with an extension of drawing those brackets around it and then writing the ion.