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Element 94 - Plutonium (Pu)
After Pluto, the planet beyond Neptune; discovered 1940. Plutonium was used, instead of uranium, in several of the first atomic bombs. In one of the codes of wartime physicists, plutonium was referred to as "copper"; copper itself had to be renamed "honest-to-God copper."
Properties
Atomic Number
:
94
Atomic Weight
:
(244)
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
5f
6
6s
2
6p
6
7s
2
Oxidation States
(Bold most stable):
+6, +5,
+4
, +3
Boiling Point
(K):
3505
Melting Point (K):
913
Density
(at 300K -- g/cm
3
):
19.84
Atomic Volume (at 300K -- cm
3
/mol)
12.32
Number of natural
radioactive
isotopes:
1
Mass Number
(Bold naturally occurring) --
Half-Life
--
Disintigration Type
:
238 -- 87.75 years --
alpha particle
emission
239
-- 2.41 x 10
4
years --
alpha particle
emission
240 -- 6.54 x 10
3
years --
alpha particle
emission
242 -- 3.8 x 10
5
years --
alpha particle
emission
244 -- 8.3 x 10
7
years --
alpha particle
emission
Covalent Radius (Å):
1.08
Atomic Radius (Å):
1.51
First
Ionization Potential
(V):
6.06
Electronegativity
(Pauling's):
1.28
Specific Heat
Capacity (at 300K -- J g
-1
K
-1
):
0.13
Electrical Conductivity (at 293K for polycrystalline material -- 10
6
-1
cm
-1
):
0.7
Thermal Conductivity (at 300K -- W m
-1
K
-1
):
6.74
Crystal Structure:
Monoclinic
Acid
-
Base
Properties:
Amphoteric