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Element 36 - Krypton (Kr)
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):
1s
2
2s
2
2p
6
3s
2
3p
6
3d
10
4s
2
4p
6
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 -- cm
3
/mol)
32.2
Number of stable
isotopes
:
6
Mass Number
(Bold naturally occurring) --
Half-Life
--
Disintigration Type
:
81 -- 2.1 x 10
5
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