Periodic Table Day
February 7 · Level 7 · #813 of 2238
This is a day for chemists and for anyone who has ever hunted for a favourite element on the big colourful chart. It celebrates the idea that all the matter around us fits on a single sheet.
How it is celebrated: teachers pin up posters of the table, classes run element quizzes, and chemistry fans share puzzles, memes and flashy lab demonstrations.
Dmitri Mendeleev published his table in 1869 and deliberately left gaps for elements nobody had found yet. Gallium, scandium and germanium later filled some of them, and element 101 now carries his name: mendelevium.