Thallium (Tl)

General Properties

Symbol Tl
Atomic Number 81
Atomic Weight 204.3833
Group
13 (boron family)
IIIB (IUPAC), IIIA (CAS)
Solid, Diamagnetic, Conductor, Metal, Stable, Natural, Poor Metal
Period 6
Block p

Physical Properties

Density 11.9 g/cm3
Atomic Volume 17.2 cm3/mole
Atomic Radius 1.71 angstroms
Covalent Radius 171 pm
Crust Abundance 0.000053%
Crystal Structure Hexagonal
Color Silver

Energy

Electronegativity 1.6 (Pauling Scale)
Electron Affinity 19.2 kJ/mol
1st Ionization Energy 589 kJ/mol
2nd Ionization Energy 1971 kJ/mol
3rd Ionization Energy 2878 kJ/mol
Specific Heat Capacity 0.129 J g−1 K−1
Thermal Conductivity 46.1 W·m−1·K−1

Electrons & Oxidation

Oxidation States +1,3
Electrons Per Shell 2 8 18 32 18 3
Electron Configuration [Xe] 4f14 5d10 6s2 6p1
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p1
Orbital Diagram
1s
↿⇂
2s
↿⇂
2p
↿⇂
↿⇂
↿⇂
3s
↿⇂
3p
↿⇂
↿⇂
↿⇂
3d
↿⇂
↿⇂
↿⇂
↿⇂
↿⇂
4s
↿⇂
4p
↿⇂
↿⇂
↿⇂
4d
↿⇂
↿⇂
↿⇂
↿⇂
↿⇂
4f
↿⇂
↿⇂
↿⇂
↿⇂
↿⇂
↿⇂
↿⇂
5s
↿⇂
5p
↿⇂
↿⇂
↿⇂
5d
↿⇂
↿⇂
↿⇂
↿⇂
↿⇂
5f
 
 
 
 
 
 
 
6s
↿⇂
6p
↿ 
 
 
6d
 
 
 
 
 
6f
 
 
 
 
 
 
 

Nuclear

Radioactive No

Media

Planetary Bohr Model of Thallium (Tl)
Lewis Dot Diagram of Thallium (Tl)
Description
Soft gray metal that looks like lead.
Uses
Its compounds are used in rat and ant poisons. Also for detecting infrared radiation.
Sources
Found in iron pyrites. Also in crookesite, hutchinsonite and lorandite. Most is recovered from the byproducts of lead and zinc refining.
Pronounciation (English)
THAL-i-em

Translations

Afrikaans Tallium
Aragonese Talio
العربية ثاليوم
Armãneashte Taliumu
asturianu Taliu
azərbaycan dili Tallium
български Таллий
বাংলা থ্যালিয়াম
brezhoneg Taliom
bosanski Talij[um]
Byelorussian Талій
Cebuano Talyo
čeština Thallium
Chuvash Талли
Cymraeg Tal·li
dansk Thallium
Deutsch Thallium
Ελληνικά Θαλλιο
English Thallium
esperanto Talio
español Talio
eesti Tallium
euskara Talioa
فارسی تالیم
suomi Tallium
føroyskt Thallium
français Thallium
furlan Tali
West-Frysk Thallium
Gaeilge Tailliam
Gàidhlig Tailliam
galego Talio
ગુજરાતી થૅલિયમનો
Gaelg Thallium
Hakka Chinese Thò (鉈)
עברית תליום
हिन्दी थैलियम
hrvatski Talij
magyar Tallium
հայերեն Թալիում
Indonesia Tallium
íslenska Þallín
italiano Tallio
日本語 タリウム
ქართული თალიუმი
کٲشُر Tôl
қазақ тілі Таллий
한국어 탈륨
Kurdish Talyûm
Komi Таллий
kernewek Thalyum
кыргызча Таллий
Latin Thallium
Lëtzebuergesch Thallium
Lombard Tàli
lingála Talu
lietuvių Talis
latviešu Tallijs
Mari Таллий
Maori Thallium
македонски Талиум
മലയാളം താലിയം
монгол Талли
Мокшан Тали
Bahasa Melayu Talium
Malti Tallju[m]
Nahuatl Talio
Nederlands Thallium
norsk Thallium
Occitan Talli
ирон Таллий
polski Tal
português Tálio
Runasimi Thalyu
română Taliu
русский Таллий
slovenčina Thallium
slovenščina Talij
Samoan Talimi
Samogitian Talis
shqip Talium, ²Thalliumi
српски Талијум
Southern Sotho Talliamo
svenska Tallium
Kiswahili Tali
தமிழ் தல்லியம்
Tajik Таллий
ไทย แทลเลียม
Türkçe Talyum
ئۇيغۇرچە تاللىي
українська Талій
o‘zbek Talliy
Tiếng Việt Tali
Võro Tallium
中文

History

Discovered In
1861
Discovered By
Sir William Crookes
Discovered At
England
Word Origin
From the Greek word "thallos" meaning "green twig" or green shoot