Kryptonite is a fictional mineral that appears in various Superman comic books and adaptations. It is typically depicted as a radioactive mineral from Superman's home planet, Krypton, and is known for its ability to weaken or even kill Superman and other Kryptonians.
In reality, however, kryptonite does not exist as a naturally occurring mineral or element. It was created as a plot device for the Superman stories. The concept of kryptonite was first introduced in 1943 on the Superman radio show, and it has since become an iconic part of Superman's mythology.
If we shift our focus to the real elements, krypton (Kr) is an actual element found on the periodic table. It is a noble gas with the atomic number 36, which means it has 36 protons in its nucleus. The symbol for krypton is "Kr," and it belongs to Group 18 (noble gases) and Period 4 of the periodic table. Krypton is chemically inert and is most commonly used in various lighting technologies, such as fluorescent lamps and lasers.