Return
to the Main CHEMystery Page.
Return
to the Periodic Table of the Elements
Element 86 - Radon (Rn)
From radium; discovered 1900. Heaviest gaseous element, it is emitted by radium and is itself
radioactive
; it
decays
into radioactive polonium and
alpha rays
. This radiation makes radon useful in cancer therapy; gold needles filled with the gas are implanted into the diseased tissue.
Properties
Atomic Number
:
86
Atomic Weight
:
(222)
Electron Configuration
(at ground state):
1s
2
2s
2
2p
6
3s
2
3p
6
3d
10
4s
2
4p
6
4d
10
5s
2
5p
6
4f
14
5d
10
6s
2
6p
6
Oxidation States
(Bold most stable):
0, +2
Boiling Point
(K):
211.4
Melting Point (K):
202
Density
(at
STP
-- g/l):
9.73
Atomic Volume (liquid state at boiling point -- cm
3
/mol)
50.5
Number of natural
radioactive
isotopes:
3
Mass Number
(Bold naturally occurring) --
Half-Life
--
Disintigration Type
:
222
-- 3.824 days --
alpha particle
emission
Atomic Radius (Å):
1.34
First
Ionization Potential
(V):
10.748
Specific Heat
Capacity (at 300K -- J g
-1
K
-1
):
0.094
Heat of Vaporization (kJ/mol):
16.40
Heat of Fusion (kJ/mol):
2.9
Thermal Conductivity (at 300K -- W m
-1
K
-1
):
0.00364
Crystal Structure:
Cubic, face centered