i don't think you would find any animation on this. but you can reffer some books which have given more clear view about bounds on atoms rather that what we learn at school. by the way keep in your mind that you are looking for a very small part of Chemistry.if you are getting ready to AL i would like to give you an advise. idon't waste your time on very simple things like this.for an example you just take a look at a AL paper. you may find one or two MCQ questins out of this section. but you have to pay your attention on more areas and need to go through this exam. if need any help just buzz me.