Terbium

Terbium is a chemical element with the symbol Tb and atomic number 65. It is a silvery-white, rare earth metal that is malleable, ductile, and soft enough to be cut with a knife. Terbium is never found in nature as a pure element, but it is contained in many rare earth minerals. It is primarily used in the production of green phosphors in cathode-ray tube televisions and fluorescent lamps.

Overview

English Name:

Terbium

Latin Name:

Terbium

Year Discovered:

1843

Discovered By:

Carl Gustaf Mosander

Group:

Period:

Electrons:

CAS Number:

7440-27-9

Cost Per 100 Grams:

$100

Atomic Properties

Electronic Configuration:

[Xe] 6s² 4f⁹

Ion Charge:

Ionisation Energies:

565.8 kJ/mol

Atomic Radius (Empirical):

178 pm

Atomic Radius (Calculated):

174 pm

Covalent Radius:

208 pm

Van Der Waals Radius:

N/A

Ionisation Potential of An Atom:

5.86 eV

Electrons Per Layer:

2, 8, 18, 27, 8, 2

Atomic Multiplicities Of The Gas:

Atomic Weight:

158.92535

Oxidation States

Reactivity

Electron Affinity:

106 kJ/mol

Valence:

Electronegativity:

1.1

Thermal Properties

Melting Point:

1356°C

Boiling Point:

2477°C

Critical Point:

Pressure: N/A

Temperature: N/A

Thermal Conductivity:

11 W/(m·K)

Heat Capacity:

Specific: 0.182 J/(g·K)

Molar: 28.91 J/(mol·K)

Thermal Coefficient:

0.000012

Enthalpy:

Fusion: 17 kJ/mol

Vaporisation: 358 kJ/mol

Atomization: 425 kJ/mol

Curie Temperature:

20°C

Neel Temperature:

N/A

Superconductivity Point:

N/A

Physical and Chemical Properties

State of matter (25° C/ 77°F):

Solid

Density:

Solid: 8.23 g/cm³

Molar Volume (Vmol):

19.32 cm³/mol

Speed of Sound (Vs):

N/A

Hardness:

1.5

Bulk Modulus (K):

54 GPa

Shear Modulus (G):

21.9 GPa

Young's Modulus (E):

64 GPa

Color:

Silvery white

Brinell Hardness (MPa):

569

Liquid Density (Kg/m^3):

7.9 g/cm³

Hardness of Mohs:

1.5

Refractive Index:

N/A

Vickers Hardness (MPa):

569

Crystal Structure:

Hexagonal

Electromagnetic Properties

Electrical Type:

Conductor

Resistivity:

5.5 × 10^-7 Ω·m

Magnetic Type:

Paramagnetic

Superconductivity:

Not applicable

Volume Magnetic Susceptibility:

1.4 × 10^-3

Mass Magnetic Susceptibility:

1.7 × 10^-9 m³/kg

Molar Mass Susceptibility:

2.7 × 10^-7 m³/mol

Electrical Conductivity:

1.8 × 10^6 S/m

Mass (γ_mass):

4.14 × 10^-26 kg

Mass (γ_mol):

4.14 × 10^-23 mol

Volume (γ_vol):

19.32 L

Grid Parameters

Crystal Structure:

Hexagonal

Grid Parameters:

a = 362.3 pm, c = 568.4 pm

Attitude:

c/a = 1.567

Debye Temperature:

N/A

Safety and Precautions

Signal Word:

Warning

Hazard Statements:

H261

Precautionary Statements:

P223, P231 + P232, P280, P335 + P334, P370 + P378

RTECS Number:

Not available

Risk:

Flammability: Flammable
Health Risk: Irritant
Reactivity: Stable
Specific Risk: Reacts with water

Importance

Main sources:

Monazite, bastnäsite

Main Usage:

Phosphors, magnets, lasers

Nuclear Properties

Radioactive:

Isotopes:

Tb-159, Tb-157, Tb-158, Tb-160

Neutron Cross Sectional:

23.4 barns

Half Life (s):

None

Lifetime:

Stable

Prevalence

Universe:

0.00007%

Sun:

0.00007%

Oceans:

0.000000007%

Humans:

0.000000015%

Earth's Crust:

0.0009%

Meteorites:

0.0009%