Thulium



69 ytterbium
-
↑
Tm
↓
Md
General
Number thulium, Tm, 69
lanthanides
Block f
Appearance silvery gray
(2)  g·mol−1
Xe] 4f13 6s2
shell 2, 8, 18, 31, 8, 2
Physical properties
Phase solid
r.t.) 9.32  g·cm−3
Liquid m.p. 8.56  g·cm−3
F)
F)
kJ·mol−1
kJ·mol−1
Heat capacity (25 °C) 27.03  J·mol−1·K−1
Vapor pressure
P(Pa) 1 10 100 1 k 10 k 100 k
at T(K) 1117 1235 1381 1570 (1821) (2217)
Atomic properties
Crystal structure hexagonal
basic oxide)
Electronegativity 1.25 (Pauling scale)
more) 1st:  596.7  kJ·mol−1
2nd:  1160  kJ·mol−1
3rd:  2285  kJ·mol−1
Atomic radius 175  pm
Atomic radius (calc.) 222  pm
Miscellaneous
Magnetic ordering no data
r.t.) (poly) 676 nΩ·m
Thermal conductivity (300 K) 16.9  W·m−1·K−1
r.t.) (poly)
13.3 µm/(m·K)
Young's modulus 74.0  GPa
Shear modulus 30.5  GPa
Bulk modulus 44.5  GPa
Poisson ratio 0.213
Vickers hardness 520  MPa
Brinell hardness 471  MPa
CAS registry number 7440-30-4
Selected isotopes
Main article: Isotopes of thulium
iso NA half-life DM DE (MeV) DP
167Tm syn 9.25 d ε 0.748 167Er
168Tm syn 93.1 d ε 1.679 168Er
169Tm 100% Tm is neutrons
170Tm syn 128.6 d β- 0.968 170Yb
171Tm syn 1.92 y β- 0.096 171Yb
References

Thulium (stable isotope Tm-169.

Contents

Applications

Thulium has been used to create laser light but high production costs have prevented other commercial uses from being developed. Other applications, real and potential:

  • When stable, thulium (Tm-169) is bombarded in a nuclear reactor it can later serve as a x-ray devices.
  • The unstable isotope Tm-171 could possibly be used as an energy source.
  • Tm-169 has potential use in ceramic magnetic materials called ferrites, which are used in microwave equipment.

History

Thulium was holmium and was named holmia by Cleve and the green substance was the oxide of an unknown element. Cleve named the oxide thulia and its element thulium after Thule, Scandinavia.

Thulium was so rare that none of the early workers had enough of it to purify sufficiently to actually see the green color; they had to be content with observing the strengthening of the two characteristic absorption bands, as erbium was progressively removed. The first researcher to obtain thulium nearly pure was the British expatriate working on a large scale at New Hampshire College in Durham NH: Charles James. In 1911, he reported his results, having used his discovered method of bromate fractional crystallization to do the purification. He famously needed 15,000 "operations" to establish that the material was homogeneous.[1]

Occurrence

The element is never found in nature in pure form, but it is found in small quantities in compounds are commercially important.

Isotopes

Main article: isotopes of thulium

Naturally occurring thulium is composed of 1 stable radioactive isotopes have half-lifes that are less than 64 hours, and the majority of these have half lifes that are less than 2 minutes. This element also has 14 meta states, with the most stable being Tm-164m (t½ 5.1 minutes), Tm-160m (t½ 74.5 seconds) and Tm-155m (t½ 45 seconds).

The isotopes of thulium range in ytterbium) isotopes.

Precautions

Thulium has a low-to-moderate acute toxic rating and should be handled with care. Metallic thulium in dust form presents a fire and explosion hazard.

Fiction

Thulium is used as intersteller money in the book Illegal Aliens (authors Nick Polotta and Phil Foglio), due to its rarity and lack of other uses.

See also

References

  1. ^ James, Charles (1911). "Thulium I". J. Am. Chem. Soc. 33 (8): 1332-1344.
  • Los Alamos National Laboratory's Chemistry Division: Periodic Table – Thulium
  • Guide to the Elements – Revised Edition, Albert Stwertka, (Oxford University Press; 1998) ISBN 0-19-508083-1
  • It's Elemental – Thulium
 
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