Kr
Krypton
Noble GasAtomic Number: 36 • Atomic Mass: 83.7980 u • Period: 4 • Group: 18
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶
Phase: Gas
Electronegativity: 3
Physical & Chemical Properties
Physical Properties
- •Colorless, odorless, tasteless noble gas
- •About three times heavier than air
- •Very low melting and boiling points
- •Poor thermal conductor
- •Gives off whitish glow in electric discharge
Melting Point
115.78 K (-157.37 °C, -251.27 °F)
Boiling Point
119.93 K (-153.22 °C, -243.80 °F)
Density
0.003733 g/cm³
Electronegativity
3 (Pauling scale)
Chemical Properties
- •Generally unreactive due to filled valence shell
- •Can form compounds with highly electronegative elements like fluorine
- •Known compounds include krypton difluoride (KrF₂)
- •Forms clathrates with water and some organic substances
- •Can be trapped in crystal lattices
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶Electron configuration describes how electrons are distributed in atomic orbitals, showing how they are arranged in energy levels and subshells.