A gift perfect for the chemist in your life or anyone who loves science. The coasters light up when you put your drink on them giving them a party feel. It features the atomic number and isotopic mass of the most stable or common isotope for each element. The radioactive elements you’ll get to choose from are Radium-226 (Red), Plutonium-244 (Blue), Uranium-238 (Green) and Thorium-232 (Orange). The Radioactive Elements Glowing Coaster Set comes in a set of 4.