What element is kr?

kr is krypton.

the chemical element symbol of Krypton is kr, and the elemental gas is a colorless, odorless and tasteless inert gas. When krypton is discharged, it glows yellow-green, and contains trace amounts in the atmosphere, which can be separated from liquid air by fractionation.

The light bulb filled with krypton is a very bright light source, which is often used to make fluorescent lamps. Krypton, like other inert gases, is extremely inert and difficult to react with other substances.

main uses:

krypton is used in some fluorescent lamps and flash lamps for high-speed photography, and as inert shielding gas in high-efficiency incandescent lamps, light bulbs and thyratrons. Radioactive krypton -85 can be used to detect cracks in closed containers, and escaped krypton atoms can be detected by their radioactivity. There is an orange-red spectral line in the light emitted by stable krypton -86, and its wavelength was used as the international standard of length meter from 196 to 1983 because of its extreme sharpness.

what are the above references? Baidu encyclopedia-kr