Radio Active Decay Analogue

Set Of 500 Cubes Of 1 Cm3 Each Packed In A Plastic Box With Lid. One Face Of Each Cube Is Black Coloured. On Throwing The Cubes, It Will Represent Atomic Nuclei, To See How Many Decay During Each Throw. Decayed Nuclei Are Removed Prior To The Next Throw. (Radio Active Decay Alogue)