Teacher Instructions for Split Pea Orbitals 1. The outer diameter of the largest circle is about 8 inches (just less than paper width) with each ringed area just about an inch in radius greater than the next smallest circle. In other words, each white or black band is about an inch thick. It's not necessary to worry about exactly how thick, so long as you make them equal thicknesses. I would imagine very thin rings would yield undesirable results. We have printed ours on standard paper and then laminated them. Printing and gluing to poster board, or printing on card stock, would probably also work. 2. The funnels we use are large, plastic, automobile-motor-oil-type funnels, not lab funnels. The stems of lab funnels get plugged up (but you probably would have figured that out before doing it. :-) ) 3. The distance from the ring stand supporting the funnel, to the table top with the target, should not be outrageously high unless you really like sweeping the floor. You can run the activity at a low height and analyze, then run again at a higher height and discuss higher energy electrons and all that good stuff. There's plenty of time in a standard 50-minute class period to do it 2x. 4. You also want to watch out for turkeys pouring the peas into your drain. yeah that's another "from experience" caution I've learned. :-)