Terbium

65
Tb
Group
n/a
Period
6
Block
f
Protons
Electrons
Neutrons
65
65
94
General Properties
Atomic Number
65
Atomic Weight
158.92535
Mass Number
159
Category
Lanthanides
Color
Silver
Radioactive
No
Terbium was named after Ytterby, a town in Sweden
Crystal Structure
Simple Hexagonal
History
Terbium was discovered in 1843 by Swedish chemist Carl Gustaf Mosander, who detected it as an impurity in yttria.

Using ammonium hydroxide he precipitated fractions of different basicity from yttria.

In these fractions he found that the fraction that was essentially colorless in solution, but gave a brown-tinged oxide was terbium.
Electrons per shell
2, 8, 18, 27, 8, 2
Electron Configuration
[Xe] 4f9 6s2
Tb
Terbium is soft enough to be cut with a knife
Physical Properties
Phase
Solid
Density
8.229 g/cm3
Melting Point
1629.15 K | 1356 °C | 2472.8 °F
Boiling Point
3503.15 K | 3230 °C | 5846 °F
Heat of Fusion
10.8 kJ/mol
Heat of Vaporization
295 kJ/mol
Specific Heat Capacity
0.182 J/g·K
Abundance in Earth's crust
0.000093%
Abundance in Universe
5×10-8%
Pure
Image Credits: Images-of-elements
Pure terbium
CAS Number
7440-27-9
PubChem CID Number
23958
Atomic Properties
Atomic Radius
177 pm
Covalent Radius
194 pm
Electronegativity
1.2 (Pauling scale)
Ionization Potential
5.8638 eV
Atomic Volume
19.20 cm3/mol
Thermal Conductivity
0.111 W/cm·K
Oxidation States
1, 3, 4
Applications
Terbium is used in alloys and in the production of electronic devices.

It is also used as a dopant for materials in solid-state devices and optical fibers.

Terbium oxide is in fluorescent lamps and TV tubes.

The brilliant fluorescence allows terbium to be used as a probe in biochemistry.
Terbium is considered to be moderately toxic
Isotopes
Stable Isotopes
159Tb
Unstable Isotopes
136Tb, 137Tb, 138Tb, 139Tb, 140Tb, 141Tb, 142Tb, 143Tb, 144Tb, 145Tb, 146Tb, 147Tb, 148Tb, 149Tb, 150Tb, 151Tb, 152Tb, 153Tb, 154Tb, 155Tb, 156Tb, 157Tb, 158Tb, 160Tb, 161Tb, 162Tb, 163Tb, 164Tb, 165Tb, 166Tb, 167Tb, 168Tb, 169Tb, 170Tb, 171Tb