boron group element
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What is the boron group in the periodic table?
The boron group, also known as Group 13 (IIIa), comprises six chemical elements: boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), and nihonium (Nh).
These elements have three electrons in their outermost atomic structure. Boron is a metalloid, while aluminum, gallium, indium, and thallium are silvery-white metals. Nihonium, the most recent addition to the group, has only been produced as individual atoms in particle accelerators.
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Which chemical elements are included in the boron group?
The boron group, also known as Group 13 (IIIa), includes six chemical elements: boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), and nihonium (Nh).
These elements have three electrons in the outermost parts of their atomic structure. Boron is a metalloid, while aluminum, gallium, indium, and thallium are silvery white metals. Nihonium, the synthetic element, has only been produced as individual atoms in particle accelerators.
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Where is the boron group located on the periodic table?
The boron group, also known as Group 13 (IIIa), is located on the periodic table. The boron group elements include boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), and nihonium (Nh). These elements are characterized by having three electrons in their outer atomic structure. Boron is a metalloid, while aluminum, gallium, indium, and thallium are silvery-white metals.
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What are some common properties of boron group elements?
Boron group elements, found in Group 13 (IIIa) of the periodic table, include boron (B), aluminum (Al), gallium (Ga), indium (In), thallium (Tl), and nihonium (Nh). These elements share a characteristic of having three electrons in their outermost shell, which influences their chemical behavior.
| Element | Property |
| --------- | ------------------------- |
| Boron | Metalloid |
| Aluminum, Gallium, Indium, Thallium | Silvery white metals |
| All | Maximum oxidation number of +3 |Boron is unique as a metalloid, while the others are silvery-white metals. Each element exhibits a maximum oxidation number of +3 due to the energy needed to remove a fourth electron from an inner shell. Boron forms covalent bonds in its compounds, facilitated by the mixing of its (s) and (p) orbitals.
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How are boron group elements used in everyday life?
The boron group elements consist of boron, aluminum, gallium, indium, thallium, and nihonium. Boron and aluminum compounds are indispensable in modern technology and have been widely used throughout recorded history.
Here's how boron group elements are used in everyday life:
- Boron Boron compounds are found in soaps, mild antiseptics, and soldering fluxes. Boric acid is a common ingredient in eye lotions and is used as a fire retardant in fabrics. Boron carbide is an extremely hard substance used as an abrasive and in composite materials. Boron is also added to steel to increase hardness and is used in the semiconductor industry to modify electrical conductivity.
- Aluminum Aluminum is used in building materials, aircraft construction, consumer durables, and in chemical and food-processing equipment. It is also added to certain metals to improve their properties.
- Gallium Gallium is used in semiconductors and optoelectronic devices.
- Indium Indium is used for coating aircraft engine bearings, in low-melting alloys for sprinkler heads and fire-door links, in semiconductor devices, and for soldering parts of germanium transistors and rectifiers.
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How do the properties of boron differ from the other elements in its group?
Boron (B) stands out from other elements in Group 13 due to its unique properties. Unlike the rest of the group, which display silvery-white, metallic characteristics, boron is a brown metalloid.
| Property | Boron | Other Group 13 Elements |
| --- | --- | --- |
| State | Metalloid | Silvery-white metals |
| Coordination | Does not form five- and six-coordinate compounds | Can be coordinated to five or six atoms |
| Flame Color | Green | Colorless, violet, or blue |
| Covalent bonding | Covalently bonded in all compounds | |Boron does not form five- and six-coordinate compounds because it lacks available d orbitals for hybridization, unlike its counterparts. Boron exhibits exclusively covalent bonding in its compounds, owing to high ionization energies. Boron compounds produce a green flame, whereas other elements in the group result in colorless, violet, or blue flames.
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boron group element, any of the six chemical elements constituting 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.
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.
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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.
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. 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.