Template:Infobox thallium

Thallium, ₈₁Tl

File:Thallium pieces in ampoule.jpg
Thallium
Pronunciation	/ˈθæliəm/ ​(THAL-ee-əm)
Appearance	silvery white
Standard atomic weight Ar°(Tl)
	[204.382, 204.385] 204.38±0.01 (abridged)
Thallium in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson In ↑ Tl ↓ Nh mercury ← thallium → lead
Atomic number (Z)	81
Group	group 13 (boron group)
Period	period 6
Block	p-block
Electron configuration	[Xe] 4f14 5d10 6s2 6p1
Electrons per shell	2, 8, 18, 32, 18, 3
Physical properties
Phase at STP	solid
Melting point	577 K ​(304 °C, ​579 °F)
Boiling point	1746 K ​(1473 °C, ​2683 °F)
Density (at 20° C)	11.873 g/cm3
when liquid (at m.p.)	11.22 g/cm3
Heat of fusion	4.14 kJ/mol
Heat of vaporization	165 kJ/mol
Molar heat capacity	26.32 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 882 977 1097 1252 1461 1758
Atomic properties
Oxidation states	common: +1, +3 −5, −2,? −1,? +2?
Electronegativity	Pauling scale: 1.62
Ionization energies	1st: 589.4 kJ/mol 2nd: 1971 kJ/mol 3rd: 2878 kJ/mol
Atomic radius	empirical: 170 pm
Covalent radius	145±7 pm
Van der Waals radius	196 pm
Color lines in a spectral range Spectral lines of thallium
Other properties
Natural occurrence	primordial
Crystal structure	​hexagonal close-packed (hcp) (hP2)
Lattice constants	Hexagonal close packed crystal structure for thallium a = 345.66 pm c = 552.52 pm (at 20 °C)
Thermal expansion	29.9 µm/(m⋅K) (at 25 °C)
Thermal conductivity	46.1 W/(m⋅K)
Electrical resistivity	0.18 µΩ⋅m (at 20 °C)
Magnetic ordering	diamagnetic
Molar magnetic susceptibility	−50.9×10−6 cm3/mol (298 K)
Young's modulus	8 GPa
Shear modulus	2.8 GPa
Bulk modulus	43 GPa
Speed of sound thin rod	818 m/s (at 20 °C)
Poisson ratio	0.45
Mohs hardness	1.2
Brinell hardness	26.5–44.7 MPa
CAS Number	7440-28-0
History
Naming	after Greek thallos, green shoot or twig
Discovery	William Crookes (1861)
First isolation	Claude-Auguste Lamy (1862)
Isotopes of thallium
Main isotopes Decay abun­dance half-life (t1/2) mode pro­duct 201Tl synth 3.0421 d ε 201Hg 203Tl 29.5% stable 204Tl synth 3.78 y β− 204Pb ε 204Hg 205Tl 70.5% stable

Tl · Thallium
Hg ← ibox Hg	iso 81 Tl  [] IB-Tl [] IBisos []	→ Pb ibox Pb
File:Symbol category class.svg cat:Tl (0) File:Symbol category class.svg cat:Tl-isotopes (0) File:Commons-logo.svg Commons File:Wikidata-logo.svg Wikidata:Q932 File:Wiktionary-logo.svg Wiktionary
indexes by PT (page)

child table, as reused in {IB-Tl}
Main isotopes of thallium
Main isotopes Decay abun­dance half-life (t1/2) mode pro­duct 201Tl synth 3.0421 d ε 201Hg 203Tl 29.5% stable 204Tl synth 3.78 y β− 204Pb ε 204Hg 205Tl 70.5% stable

Data sets read by {{Infobox element}}
Name and identifiers
Symbol etymology (11 non-trivial)
Top image (caption, alt)	caption: alt:
Pronunciation
Allotropes (overview)
Group (overview)
Period (overview)
Block (overview)
Natural occurrence
Phase at STP
Oxidation states
Spectral lines image
Electron configuration (cmt, ref)
Isotopes
Standard atomic weight
most stable isotope
File:Notification-icon-Wikidata-logo.svg Wikidata
Wikidata *
* Not used in {{Infobox element}} (2023-01-01) See also {{Index of data sets}} · Cat:data sets (0) · (this table: )

References

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