Krypton
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Atomic symbol: Kr
Atomic number: 36
Atomic mass: 83.80
Appearance: Colorless gas at 25°C
Group: 0 / 18
Period: 4
Series: Noble gases
Block: p
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶
Used in fluorescent lighting since it exhibits a whitish glow in an electric field.
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Solid kryptonite is white and crystalline.
Fun Fact! Krypton is named after the Ancient Roman ‘kryptos’, meaning “the hidden one”, in keeping with its properties as a colorless, odorless, tasteless, chemical inert gas, that make it hard to detect.