Atomic number 69
Group, block group n/a, f-block
Period period 6
Element category lanthanide
Standard atomic weight (±) (Ar) 168.93422(2)1
Electron configuration Xe 4f13 6s2
per shell
2, 8, 18, 31, 8, 2
Physical properties
Phase solid
Melting point 1818 K (1545 °C, 2813 °F)
Boiling point 2223 K (1950 °C, 3542 °F)
Density near r.t. 9.32 g/cm3
when liquid, at m.p. 8.56 g/cm3
Heat of fusion 16.84 kJ/mol
Heat of vaporization 191 kJ/mol
Molar heat capacity 27.03 J/(mol·K)
vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1117 1235 1381 1570 (1821) (2217)
Atomic properties
Oxidation states 2, 3 (a basic oxide)
Electronegativity Pauling scale: 1.25
Ionization energies 1st: 596.7 kJ/mol
2nd: 1160 kJ/mol
3rd: 2285 kJ/mol
Atomic radius empirical: 176 pm
Covalent radius 190±10 pm
Crystal structure hexagonal close-packed (hcp) Hexagonal close packed crystal structure for thulium
Thermal expansion poly: 13.3 µm/(m·K) (at r.t.)
Thermal conductivity 16.9 W/(m·K)
Electrical resistivity poly: 676 nΩ·m (at r.t.)
Magnetic ordering paramagnetic (at 300 K)
Young's modulus 74.0 GPa
Shear modulus 30.5 GPa
Bulk modulus 44.5 GPa
Poisson ratio 0.213
Vickers hardness 470–650 MPa
Brinell hardness 470–900 MPa
CAS Number 7440-30-4
Naming after Thule, a mythical region in Scandinavia
Discovery and first isolation Per Teodor Cleve (1879)
My Thulium dissolved into a dilute sulfuric acid last night, While I was studying the 69 electrons surrounding the nucleus.
by S.C.S.C.S.C.S.Cena August 07, 2016
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A whole number between 68 and 70.
Now, let's turn the book to page 69!
by DinoCoat May 13, 2017
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Such an innocent number! Why do people think it is dirty?
Teacher: What comes after 68 dear?
Kid: 69!
Teacher: correct!
by Elbert Ainstein October 10, 2014
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The jersey number commonly worn by the fattest guy on every football team.
Billy Bob is fat, so he wears the 69 jersey to boost his sex appeal.
by futbol_fan January 31, 2010
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when 2 partners give oral pleasureing on top of each other at the same exact time.
69 man eats the taco (vagina, pussy, cave, etc..) and while woman sucks on the straw (penis, dick, hot-dog, tube-steak, meat, etc..). you see how the 6 and the 9 are upside the mean cock suck and pussy lick.
by slg gabbard April 22, 2006
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