Tl Element

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  1. Tl Element Electrons And Protons
  2. Thallium-201 Tl - PubChem
  3. Tl Element
  4. Tl Element Abbreviation
  • General properties of the group
    • Compounds of the boron group elements
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Alternative Titles: Group 13 element, Group IIIa element, aluminum group element

Boron group element, any of the six chemical elementsconstituting Group 13 (IIIa) of the periodic table. The elements are boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), and nihonium (Nh). They are characterized as a group by having three electrons in the outermost parts of their atomic structure. Boron, the lightest of these elements, is a metalloid. Aluminum, gallium, indium, and thallium are silvery white metals. Nihonium has only been produced as individual atoms in particle accelerators.

Periodic Table of the Elements
Test your bond with the periodic table of elements in this quiz on all 118 chemical elements and their symbols. You may be familiar with the chemical symbols for hydrogen and oxygen, but can you match such lower-profile elements as gadolinium and erbium with their corresponding symbols?

None of these elements was known in a pure state before modern chemistry isolated them. Very soon after a method had been found to produce it in commercial quantities, aluminum revolutionized industry. With further development of science and technology, specifically in nanotechnology, boron gained significant attention in industrial sectors as well. The other members of the group still have little commercial value. Some of the compounds of boron and aluminum, however, are indispensable in modern technology and have been widely used in many parts of the world throughout recorded history.

History

The use of a boron compound known as borax (sodium tetraborate, Na2B4O7∙10H2O) can be traced back to the ancient Egyptians, who used it as a metallurgical flux (a substance that aids the heat joining or soldering of metals), in medicine, and in mummification. During the 13th century Marco Polo introduced borax into Europe, but not until the mid-19th century, when vast deposits of borates were discovered in the Mojave Desert, did borax become relatively common. The ancient Egyptians, Greeks, and Romans used a compound of aluminum known as alum (the compound potassium aluminum sulfate) in dyeing as a mordant—i.e., a substance that fixes dye molecules to the fabric. Lapis lazuli, a rare dark blue mineral (the compound sodium aluminum silicate containing sulfur), has been widely used as a semiprecious stone throughout history. The metal aluminum was first isolated early in the 19th century, but it was not until a modern electrolytic process based on the use of bauxite ore had been developed that commercial production of aluminum became economically feasible. Three other boron group elements—gallium, indium, and thallium—were first detected spectroscopically (i.e., by analysis of the light emitted by or passed through substances containing the element) in the late 19th century. The existence and properties of gallium were predicted by a Russian chemist, Dmitry Ivanovich Mendeleyev, on the basis of the periodic table of the elements that he had developed; the ultimate discovery of gallium and the accuracy of his description of the properties of the then unknown element convinced scientists of the theoretical soundness of the table. Gallium is one of two metals (the other is cesium) whose melting points are low enough for them to turn to liquid when held in the hand. Nihonium was artificially produced in a particle accelerator in 2004.

General properties of the group

Ionization energies

Every element in the boron group has three electrons in its outermost shell (so-called valence electrons), and for each element there is a sharp jump in the amount of energy required to remove the fourth electron, reflecting the fact that this electron must be removed from an inner shell. Consequently, the elements of the group have maximum oxidation numbers of three, corresponding to loss of the first three electrons, and form ions with three positive charges.

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The apparently erratic way in which ionization energies vary among the elements of the group is due to the presence of the filled inner d orbitals in gallium, indium, and thallium, and the f orbital in thallium, which do not shield the outermost electrons from the pull of the nuclear charge as efficiently as do the inner s and p electrons. In Groups 1 and 2 (Ia and IIa), in contrast to the boron group, outer shell (always referred to as n) electrons are shielded in every case by a constant inner set of electrons, in the (n-1)s2(n-1)p6 orbitals, and the ionization energies of these Group-1 and Group-2 elements decrease smoothly down the group. The ionization energies of gallium, indium, and thallium are thus higher than expected from their Group 2 counterparts because their outer electrons, being poorly shielded by the inner d and f electrons, are more strongly bound to the nucleus. Riot phreak twitch. This shielding effect also makes the atoms of gallium, indium, and thallium smaller than the atoms of their Group 1 and 2 neighbours by causing the outer electrons to be pulled closer toward the nucleus.

The M3+ state for gallium, indium, and thallium is energetically less favourable than Al3+ because the high ionization energies of these three elements cannot always be balanced by the crystal energies of possible reaction products. For example, of the simple, anhydrous compounds of thallium in its +3 oxidation state, only the trifluoride, TlF3, is ionic. For the group as a whole, therefore, the M3+ ionic state is the exception rather than the rule. More commonly the elements of the group form covalent bonds and achieve an oxidation state of three by promoting one electron from the s orbital in the outer shell (designated ns orbital) to an np orbital, the shift permitting the formation of hybrid, or combination, orbitals (of the variety designated as sp2). Increasingly down the group there is a tendency toward the formation of M+ ions, and at thallium the +1 oxidation state is the more stable one. The basicity (a property of metals) of the elements also increases in proceeding down the group, as shown by the oxides they form: boric oxide (formula B2O3) is acidic; the next three oxides, of aluminum, gallium, and indium (formulas Al2O3, Ga2O3, and In2O3) are either acidic or basic depending on the environment (a property called amphoterism); and thallic oxide (Tl2O3) is wholly basic.

Quick Facts
related topics

The elements of the periodic table sorted by name in an alphabetical list.

Click on any element's name for further chemical properties, environmental data or health effects.

Tl Element

This list contains the 118 elements of chemistry.

Element
The chemical elements of
the periodic chart sorted by:

Name chemical element

Symbol

Atomic number

- Name alphabeticallyActiniumAc89
- Atomic numberAluminumAl13
- SymbolAmericiumAm95
- Atomic MassAntimonySb51
- ElectronegativityArgonAr18
- DensityArsenicAs33
- Melting pointAstatineAt85
- Boiling pointBariumBa56
- Vanderwaals radiusBerkeliumBk97
- Year of discoveryBerylliumBe4
- Inventor surnameBismuthBi83
- Elements in earthcrustBohriumBh107
- Elements in human bodyBoronB5
- Covalent RadiusBromineBr35
- Ionization energyCadmiumCd48

For chemistry students and teachers: The tabular chart on the right is alphabethically listed.

The first chemical element is Actinium and the last is Zirconium.

Please note that the elements do not show their natural relation towards each other as in the Periodic system. There you can find the metals, semi-conductor(s), non-metal(s), inert noble gas(ses), Halogens, Lanthanoides, Actinoids (rare earth elements) and transition metals.

CalciumCa20
CaliforniumCf98
CarbonC6
CeriumCe58
CesiumCs55
ChlorineCl17
ChromiumCr24
CobaltCo27
CoperniciumCn112
CopperCu29
CuriumCm96
DarmstadtiumDs110
DubniumDb105
DysprosiumDy66
EinsteiniumEs99
ErbiumEr68
EuropiumEu63
FermiumFm100
Flerovium Fl114
FluorineF9
FranciumFr87
GadoliniumGd64
GalliumGa31
GermaniumGe32
GoldAu79
HafniumHf72
HassiumHs108
HeliumHe2
HolmiumHo67
HydrogenH1
IndiumIn49
IodineI53
IridiumIr77
IronFe26
KryptonKr36
LanthanumLa57
LawrenciumLr103
LeadPb82
LithiumLi3
Livermorium Lv116
LutetiumLu71
MagnesiumMg12
ManganeseMn25
MeitneriumMt109
MendeleviumMd101
MercuryHg80
MolybdenumMo42
Moscovium Mc115
NeodymiumNd60
NeonNe10
NeptuniumNp93
NickelNi28
Nihonium Nh113
NiobiumNb41
NitrogenN7
NobeliumNo102
Oganesson Og118
OsmiumOs76
OxygenO8
PalladiumPd46
PhosphorusP15
PlatinumPt78
PlutoniumPu94
PoloniumPo84
PotassiumK19
PraseodymiumPr59
PromethiumPm61
ProtactiniumPa91
RadiumRa88
RadonRn86
RheniumRe75
RhodiumRh45
RoentgeniumRg111
RubidiumRb37
RutheniumRu44
RutherfordiumRf104
SamariumSm62
ScandiumSc21
SeaborgiumSg106
SeleniumSe34
SiliconSi14
SilverAg47
SodiumNa11
StrontiumSr38
SulfurS16
TantalumTa73
TechnetiumTc43
TelluriumTe52
Tennessine Ts117
TerbiumTb65
ThalliumTl81
ThoriumTh90
ThuliumTm69
TinSn50
TitaniumTi22
TungstenW74
UraniumU92
VanadiumV23
XenonXe54
YtterbiumYb70
YttriumY39
ZincZn30
ZirconiumZr40

Click here: for a schematic overview of the periodic table of elements in chart form

Do you need to know the weight of some molecules? Try our Molecular Weight Calculator!

Please report any accidental mistake in the above statistics on chemical elements.

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