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Element 65 - Terbium (Tb)
From Ytterby, Sweden; discovered 1843; named after the town that also gave its name to three other elements; the rare earths ytterbium and erbium and the transitional metal yttrium. Like all rare earths, terbium in an impure state is pyrophoric--i.e., it bursts into flames when heated.
Properties
Atomic Number
:
65
Atomic Weight
:
158.9253
Electron Configuration
(at ground state):
1s
2
2s
2
2p
6
3s
2
3p
6
3d
10
4s
2
4p
6
4d
10
4f
9
5s
2
5p
6
6s
2
Oxidation States
(Bold most stable):
+3
, +4
Boiling Point
(K):
3500
Melting Point (K):
1629
Density
(at 300K -- g/cm
3
):
8.23
Atomic Volume (at 300K -- cm
3
/mol)
19.2
Number of stable
isotopes
:
1
Mass Number
(Bold naturally occurring) --
Half-Life
--
Disintigration Type
:
158 -- 1.2 x 10
3
years -- orbital
electron capture
,
beta particle
(
electron
) emission
160 -- 72.3 days --
beta particle
(
electron
) emission
Covalent Radius (Å):
1.59
Atomic Radius (Å):
1.80
First
Ionization Potential
(V):
5.86
Electronegativity
(Pauling's):
1.1
Specific Heat
Capacity (at 300K -- J g
-1
K
-1
):
0.18
Electrical Conductivity (at 293K for polycrystalline material -- 10
6
-1
cm
-1
):
0.9
Thermal Conductivity (at 300K -- W m
-1
K
-1
):
11.1
Crystal Structure:
Hexagonal
Acid
-
Base
Properties:
Slightly basic