Tl Thallium – Element Information, Facts, Properties, Trends,Uses, Comparison with other elements

81
Tl
Thallium

Thallium

Element 81 of Periodic table is Thallium with atomic number 81, atomic weight 204.3833. Thallium, symbol Tl, has a Simple Hexagonal structure and Silver color. Thallium is a post-transition metal element. Trivial name of Thallium is triels, icosagens. Know everything about Thallium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.

81 Tl - Thallium | SchoolMyKids

Thallium is a chemical element with symbol Tl and atomic number 81. This soft gray post-transition metal is not found free in nature. When isolated, it resembles tin, but discolors when exposed to air.

How to Locate Thallium on Periodic Table

Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 81 to find Thallium on periodic table.

Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Thallium on periodic table look for cross section of group 13 and period 6 in the modern periodic table.

Table of Contents

Thallium History

The element Thallium was discovered by William Crookes in year 1861 in United Kingdom . Thallium derived its name from the Greek thallos, 'green twig'

Thallium Presence: Abundance in Nature and Around Us

The table below shows the abundance of Thallium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.

  Ppb by weight (1ppb =10^-7 %)
Abundance in Universe 5×10-8%
Abundance in Sun 1×10-7%
Abundance in Meteorites 7.8×10-6%
Abundance in Earth's Crust 5.3e-07
Abundance in Oceans 1×10-10%
Abundance in Humans N/A

Crystal Structure of Thallium

The solid state structure of Thallium is Simple Hexagonal.

The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.

Unit Cell Parameters

The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)

a b c
345.66 345.66 552.48 pm

and the angles between them Lattice Angles (alpha, beta and gamma).

alpha beta gamma
π/2 π/2 2 π/3

The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.

The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.

Space Group Name P63/mmc 81 Tl Thallium - Crystal Structure | SchoolMyKids
Space Group Number 194
Crystal Structure Simple Hexagonal

Thallium Atomic and Orbital Properties

Thallium atoms have 81 electrons and the electronic shell structure is [2, 8, 18, 32, 18, 3] with Atomic Term Symbol (Quantum Numbers) 2P1/2.

Atomic Number 81
Number of Electrons (with no charge) 81
Number of Protons 81
Mass Number 204
Number of Neutrons 123
Shell structure (Electrons per energy level) [2, 8, 18, 32, 18, 3]
Electron Configuration [Xe] 4f14 5d10 6s2 6p1
Valence Electrons 6s2 6p1
Oxidation State -5;-2;-1
1;2;3
Atomic Term Symbol (Quantum Numbers) 2P1/2

Shell Structure of Thallium - Electrons per energy level

81 Tl Thallium - Electron Shell Structure | SchoolMyKids
n s p d f
1 K 2
2 L 2 6
3 M 2 6 10
4 N 2 6 10 14
5 O 2 6 10
6 P 2 1

Ground State Electronic Configuration of Thallium - neutral Thallium atom

The ground state electronic configuration of Neutral Thallium atom is [Xe] 4f14 5d10 6s2 6p1. The portion of Thallium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Xe]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used.This is important as it is the Valence electrons 4f14 5d10 6s2 6p1, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Thallium

Complete ground state electronic configuration for the Thallium atom, Unabbreviated electronic configuration

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d10 6s2 6p1

Atomic Structure of Thallium

Thallium atomic radius is 156 pm, while it's covalent radius is 148 pm.

Atomic Radius

156 pm (1.56 Å)

Atomic Volume 17.247535865 cm3
Covalent Radius 148 pm (1.48 Å)
Van der Waals Radius 196 pm
Neutron Cross Section 3.4 σa/barns

Atomic Spectrum of Thallium

Atomic Spectrum of Thallium | SchoolMyKids

Thallium Chemical Properties: Thallium Ionization Energies and electron affinity

The electron affinity of Thallium is 19.2 kJ/mol

Valence 3
Electronegativity 1.62
ElectronAffinity 19.2 kJ/mol

Ionization Energy of Thallium

Refer to table below for Ionization energies of Thallium

Ionization energy number Enthalpy - kJ/mol
1 589.4
2 1971
3 2878

Thallium Physical Properties

Refer to below table for Thallium Physical Properties

Density 11.85 g/cm3
Molar Volume 17.247535865 cm3

Elastic Properties

Young Modulus 8 GPa
Shear Modulus 2.8 GPa
Bulk Modulus 43 GPa
Poisson Ratio 0.45

Hardness of Thallium - Tests to Measure of Hardness of Element

Mohs Hardness 1.2 MPa
Vickers Hardness N/A
Brinell Hardness 26.4 MPa

Thallium Electrical Properties

Thallium is Conductor of electricity. Refer to table below for the Electrical properties of Thallium

Electrical Conductivity 6.7×106 S/m
Resistivity 1.5×10-7 m Ω
Superconducting Point 2.38

Thallium Heat and Conduction Properties

Thermal Conductivity 46 W/(m K)
Thermal Expansion 0.0000299 K-1

Thallium Magnetic Properties

Magnetic Type Diamagnetic
Curie Point N/A
Mass Magnetic Susceptibility -3×10-9
Molar Magnetic Susceptibility -6.13×10-10
Volume Magnetic Susceptibility -3.56e-05

Optical Properties of Thallium

Refractive Index N/A

Acoustic Properties of Thallium

Speed of Sound 818 m/s

Thallium Thermal Properties - Enthalpies and thermodynamics

Refer to table below for Thermal properties of Thallium

Melting Point 577 K (304 °C)
Boiling Point 1746 K (1473 °C)
Critical Temperature N/A
Superconducting Point 2.38

Enthalpies of Thallium

Heat of Fusion 4.2 kJ/mol
Heat of Vaporization 165 kJ/mol
Heat of Combustion N/A

Thallium Isotopes - Nuclear Properties of Thallium

Isotopes of rhodium. Naturally occurring Thallium has 2 stable isotope - 203Tl, 205Tl.

Isotope Isotope Mass % Abundance T half Decay Mode
176Tl  
177Tl  
178Tl  
179Tl  
180Tl  
181Tl  
182Tl  
183Tl  
184Tl  
185Tl  
186Tl  
187Tl  
188Tl  
189Tl  
190Tl  
191Tl  
192Tl  
193Tl  
194Tl  
195Tl  
196Tl  
197Tl  
198Tl  
199Tl  
200Tl  
201Tl  
202Tl  
203Tl   29.524% Stable N/A
204Tl  
205Tl   70.476% Stable N/A
206Tl  
207Tl  
208Tl  
209Tl  
210Tl  
211Tl  
212Tl  

Regulatory and Health - Health and Safety Parameters and Guidelines

CAS Number CAS7440-28-0
RTECS Number RTECSXG3425000
DOT Hazard Class N/A
DOT Numbers 1707
EU Number N/A
NFPA Fire Rating N/A
NFPA Hazards N/A
NFPA Health Rating N/A
NFPA Reactivity Rating N/A
Autoignition Point N/A
Flashpoint N/A

Database Search

List of unique identifiers to search the element in various chemical registry databases

Database Identifier number
CAS Number - Chemical Abstracts Service (CAS) CAS7440-28-0
CID Number CID5359464
Gmelin Number N/A
NSC Number N/A
RTECS Number RTECSXG3425000

List of Elements
1 H - Hydrogen
2 He - Helium
3 Li - Lithium
4 Be - Beryllium
5 B - Boron
6 C - Carbon
7 N - Nitrogen
8 O - Oxygen
9 F - Fluorine
10 Ne - Neon
11 Na - Sodium
12 Mg - Magnesium
13 Al - Aluminium
14 Si - Silicon
15 P - Phosphorus
16 S - Sulfur
17 Cl - Chlorine
18 Ar - Argon
19 K - Potassium
20 Ca - Calcium
21 Sc - Scandium
22 Ti - Titanium
23 V - Vanadium
24 Cr - Chromium
25 Mn - Manganese
26 Fe - Iron
27 Co - Cobalt
28 Ni - Nickel
29 Cu - Copper
30 Zn - Zinc
31 Ga - Gallium
32 Ge - Germanium
33 As - Arsenic
34 Se - Selenium
35 Br - Bromine
36 Kr - Krypton
37 Rb - Rubidium
38 Sr - Strontium
39 Y - Yttrium
40 Zr - Zirconium
41 Nb - Niobium
42 Mo - Molybdenum
43 Tc - Technetium
44 Ru - Ruthenium
45 Rh - Rhodium
46 Pd - Palladium
47 Ag - Silver
48 Cd - Cadmium
49 In - Indium
50 Sn - Tin
51 Sb - Antimony
52 Te - Tellurium
53 I - Iodine
54 Xe - Xenon
55 Cs - Cesium
56 Ba - Barium
57 La - Lanthanum
58 Ce - Cerium
59 Pr - Praseodymium
60 Nd - Neodymium
61 Pm - Promethium
62 Sm - Samarium
63 Eu - Europium
64 Gd - Gadolinium
65 Tb - Terbium
66 Dy - Dysprosium
67 Ho - Holmium
68 Er - Erbium
69 Tm - Thulium
70 Yb - Ytterbium
71 Lu - Lutetium
72 Hf - Hafnium
73 Ta - Tantalum
74 W - Tungsten
75 Re - Rhenium
76 Os - Osmium
77 Ir - Iridium
78 Pt - Platinum
79 Au - Gold
80 Hg - Mercury
81 Tl - Thallium
82 Pb - Lead
83 Bi - Bismuth
84 Po - Polonium
85 At - Astatine
86 Rn - Radon
87 Fr - Francium
88 Ra - Radium
89 Ac - Actinium
90 Th - Thorium
91 Pa - Protactinium
92 U - Uranium
93 Np - Neptunium
94 Pu - Plutonium
95 Am - Americium
96 Cm - Curium
97 Bk - Berkelium
98 Cf - Californium
99 Es - Einsteinium
100 Fm - Fermium
101 Md - Mendelevium
102 No - Nobelium
103 Lr - Lawrencium
104 Rf - Rutherfordium
105 Db - Dubnium
106 Sg - Seaborgium
107 Bh - Bohrium
108 Hs - Hassium
109 Mt - Meitnerium
110 Ds - Darmstadtium
111 Rg - Roentgenium
112 Cn - Copernicium
113 Nh - Nihonium
114 Fl - Flerovium
115 Mc - Moscovium
116 Lv - Livermorium
117 Ts - Tennessine
118 Og - Oganesson
Metalloid
Nonmetals
Other Nonmetals
Halogens Noble Gas
Metals
Alkali Metals Alkaline Earth Metals
Transition Metals Post-Transition Metals
Lanthanide Actinide