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Element 36 - Krypton (Kr) sound

From kryptos, or hidden; discovered in 1898. Radioactive krypton was used to keep tabs on Soviet nuclear production. Because this gas is a by-product of all nuclear reactors, the Russian share is found by subtracting the amount that comes from Western reactors from the total in the air.

Properties

Atomic Number: 36
Atomic Weight: 83.80
Electron Configuration (at ground state): 1s22s22p63s23p63d104s24p6
Oxidation States (Bold most stable): 0, +2
Boiling Point (K): 120.85
Melting Point (K): 116
Density (at STP -- g/l): 3.75
Atomic Volume (liquid state at boiling point -- cm3/mol) 32.2
Number of stable isotopes: 6
Mass Number (Bold naturally occurring) -- Half-Life -- Disintigration Type: 81 -- 2.1 x 105 years -- orbital electron capture
85 -- 10.72 years -- beta particle (electron) emission
Covalent Radius (Å): 1.89
Atomic Radius (Å): 1.03
First Ionization Potential (V): 13.999
Specific Heat Capacity (at 300K -- J g-1 K-1): 0.248
Heat of Vaporization (kJ/mol): 9.029
Heat of Fusion (kJ/mol): 1.638
Thermal Conductivity (at 300K -- W m-1 K-1): 0.00949
Crystal Structure: Cubic, face centered