Played with in great shape, see pictures From the Website: Probably the only time you should let a child play with Plutonium and Arsenic. Each colorful block features six element images accompanied by their atomic number, symbol, and name. Mad scientists of all ages love these blocks. The vibrant and vivid colors capture the eye and excite imaginations. Adults claim to get these blocks for children...but often get sets for themselves, as well. Who can blame them? Periodic Table Blocks make for a colorful display, but are also fun for playing, learning, and advancing scientific discussions. 20 - 1.75 inch cubes Made using sustainable Midwestern basswood Printed with safe-to-touch inks 100% made in the USA Ages 2+