Yes, after years and years of meaning to get this done I am *finally* getting to it. Yes, it took oldest dd entering high school and taking Chemistry to provide the official push. Isn't that sad?? And yes, I WILL finish it this time!!
I'm having to rethink all of my thoughts and plans and reinvestigate. But this benefits you because I'll post links, ideas, measurements, etc along the way.
Here is a beautiful model made from a precut table top that you can find at most home improvement stores. Brilliant! Mine will be made out of foam board from the dollar store (humble shrug). She used marbles for all three (neutrons, protons, electrons) but since mine will be smaller I will use pony beads for neutrons/ protons and marbles for electrons only. Years ago this poster was on the Montessori groups and was so incredibly helpful when I was starting out and needed someone (several people!) to hold my hand through it all.
Here is another wonderful example. It looks like it is made from a lighter wood.
Mine won't be as nice as the wooden ones, but it will be done... and there's a lot to be said for done :). I practiced a while back (probably last summer!) and if I poke a pencil all of the way through the foam board it is perfect to hold a marble. Pretty high tech, eh?
Plans: 10 inch square piece of foam board for the base; 2 inch diameter circular hole in the center to hold the little container for the nucleus; 1-1/2 inches in between each concentric circle; the holes for the marbles (aka electrons) within the orbital spaces.
Problems: Cutting a nice circle in the center; finding their marbles!
For the filling it says that "for an easier version, sub the filling with 2 cups of fig preserves." I recently made fig jam and really it's just figs and sugar. So, I plan on dumping my home-canned figs in a pot (which are in a light sugar syrup), trimming the stems, mashing, and simmering until it gets thick. The whole point of my searching for the recipe was to use the canned figs anyway.
Now I'm off to get the Fig Newtons ready to bake at a friend's house (still no oven) and to find my marbles :).