Group 3A

12 Key excerpts on "Group 3A"

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  eBook - PDF

  Essentials of Inorganic Chemistry

  For Students of Pharmacy, Pharmaceutical Sciences and Medicinal Chemistry

  • Katja A. Strohfeldt(Author)
  • 2014(Publication Date)
  • Wiley

    (Publisher)

  4 The Boron Group – Group 13 Group 13 (13th vertical column of the periodic table) is called the boron group and it consists of boron (B), aluminium (Al), gallium (Ga), indium (In) and thallium (Tl) (Figure 4.1). All elements within group 13 show a wide variety of properties. It is important to note that boron is a metal- loid (semi-metal) whereas aluminium is a metal but shows many chemical similarities to boron. Aluminium, gallium, indium and thallium are considered to be metals of the ‘poor metals’ group. Metalloids are elements that display some properties characteristic for metals and some characteristic for nonmetals. In this chapter, the general chemistry of group 13 elements is discussed as well as some clinical applications for boron and aluminium. Further clinical applications for boron as well as applications for thallium can be found in the chapter on radiochemistry (Chapter 10). 4.1 General chemistry of group 13 elements Group 13 elements are characterised by having three electrons in their valence shell. Therefore, all elements form the stable cation M 3+ . Most elements (with the exception of B) form additionally the singly positively charged ion M + , which is indeed the more stable oxidation state for Tl. Boron and aluminium occur only with oxidation number +3 in their compounds, and with a few exceptions their compounds are best described as ionic. The electronic configuration shows three electrons outside a noble gas configuration, two in an s shell and one in a p shell. The outermost p electron is easy to remove as it is furthest from the nucleus and well shielded from the effective nuclear charge. The next two s electrons are also relatively easy to remove. Removal of any further electrons disturbs a filled quantum shell and is therefore difficult. This is reflected in the ionisation energies (Table 4.1).

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  eBook - ePub

  Essentials of Inorganic Chemistry

  For Students of Pharmacy, Pharmaceutical Sciences and Medicinal Chemistry

  • Katja A. Strohfeldt(Author)
  • 2015(Publication Date)
  • Wiley

    (Publisher)

  Chapter 4 The Boron Group – Group 13

  Group 13 (13th vertical column of the periodic table) is called the

  boron group

  and it consists of boron (B), aluminium (Al), gallium (Ga), indium (In) and thallium (Tl) (Figure 4.1 ).

  Figure 4.1

  The periodic table of elements, group 13 elements are highlighted

  All elements within group 13 show a wide variety of properties. It is important to note that boron is a metalloid (semi-metal) whereas aluminium is a metal but shows many chemical similarities to boron. Aluminium, gallium, indium and thallium are considered to be metals of the ‘poor metals’ group.

  Metalloids are elements that display some properties characteristic for metals and some characteristic for nonmetals.

  In this chapter, the general chemistry of group 13 elements is discussed as well as some clinical applications for boron and aluminium. Further clinical applications for boron as well as applications for thallium can be found in the chapter on radiochemistry (Chapter 10).

  4.1 General chemistry of group 13 elements

  Group 13 elements are characterised by having three electrons in their valence shell. Therefore, all elements form the stable cation M3+ . Most elements (with the exception of B) form additionally the singly positively charged ion M+ , which is indeed the more stable oxidation state for Tl.

  Boron and aluminium occur only with oxidation number +3 in their compounds, and with a few exceptions their compounds are best described as ionic. The electronic configuration shows three electrons outside a noble gas configuration, two in an s shell and one in a p shell. The outermost p electron is easy to remove as it is furthest from the nucleus and well shielded from the effective nuclear charge. The next two s electrons are also relatively easy to remove. Removal of any further electrons disturbs a filled quantum shell and is therefore difficult. This is reflected in the ionisation energies (Table 4.1

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  Trace Elements in Soils and Plants

  • Alina Kabata-Pendias(Author)
  • 2010(Publication Date)
  • CRC Press

    (Publisher)

  315 18 Elements of Group 13 (Previously Group IIIa) The Group 13 consists of five elements: boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (TI). These elements have three electrons in their outer energy levels, thus their valence is mainly + 3 (Table 18.1). Geochemical and biochemical properties, as well as the abundance in the biosphere, of all these elements are highly divergent. Their common characteristic is a strong affin-ity for oxygen. Among them, only B is metalloid (nonmetal) and plays a significant role in plants. Aluminum, being one of the basic constituents of the lithosphere, reveals amphoteric properties. Three other trace metals (Ga, In, and Tl) are widely, but at low concentrations, distributed in the lithosphere and biosphere. BORON I I NTRODUCTION A Boron is widely but not uniformly distributed in the environment and averages 15 mg/g in the Earth’s crust (Tables 3.2 and 18.2). Its contents in igneous rocks range from 5 to 30 mg/kg and increases with the acidity of rocks. In sedimentary rocks its content is higher than in igneous rocks and is closely associated with the clay fraction. Its common minerals are: borax, Na 2 B 4 O 7 ⋅ 10H 2 O; colemanite, Ca 2 B 6 O 11 ⋅ 5H 2 O; ulexite, NaCaB 5 O 9 ⋅ 8H 2 O; kernite, Na 2 B 4 O 6 ⋅ 3H 2 O; and tourmalines of a very complex composition. B might be associated with feldspars and micas. Its concentrations are elevated in carboniferous sediments and some coals. 1357 It is likely to be concentrated in fly ash, where its mean content is estimated as 509 mg/kg (Llorens et al., 2000). B has a high affinity for oxygen, due to which it occurs in the nature mainly as B–O compounds. Its chemical properties resemble that of Si. The global B production in 2008 was 4.1 Mt (USDI, 2009). Borate deposits are quite rare and generally found in arid regions, with a history of volcanism or hydrothermal activities.

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  Comparative Inorganic Chemistry

  • Bernard Moody(Author)
  • 2013(Publication Date)
  • Arnold

    (Publisher)

  19 Group III: the boron group Boron and aluminium Boron is the most electro-negative element of Group III and has little in common with the other elements. It is non-metallic. This is the first group in which the change from the non-metallic to-wards the metallic condition occurs with increasing atomic number. The de-tailed chemistry of alumin-ium and its compounds will be described, while of the other elements, selected compounds of boron only are included. Group III is unusual. Reference to the open form of the Periodic Table reveals that the group is placed to the right of the gap opened for the inclu-sion of transition and associated metals. It is the first group of the p block elements. No elements separate beryllium and boron in Period 2, or magnesium and aluminium in Period 3, but in the successive periods scandium (21), yttrium (39), lan-thanum (57) and actinium (89) appear as the first members of transition series, formed by successive expansion of penultimate electron shells. In addi-tion, Periods 6 and 7 contain the inner transition series, lanthanides and actinides. Scandium, yttrium, lanthanum and actinium form the A sub-group of the Mendeléeff Table while the B sub-group consisted of gallium, indium and thallium. The subgroups are very much more alike than in the previous groups. However, only boron and alu-minium will be considered further. Both have un-usual properties. Aluminium is on the 'diagonal borderland' between metals and non-metals in the chemical sense. The most widely known compound of boron is borax, the name being derived from an Arabic word given to fluxes in general. Impure boron was first isolated in 1808 by Gay-Lussac and Thénard using reduction of boric oxide with potassium. Aluminium was isolated by the reduction of an-hydrous aluminium chloride with potassium by Oersted (1825) and Wöhler (1827). The name is derived from a general term for astringents, alumen.

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  The Periodic Table

  A visual guide to the elements

  • Tom Jackson(Author)
  • 2020(Publication Date)
  • White Lion Publishing

    (Publisher)

  = liquid = solid = gas = non-metal = metal = metalloid = unknown 0 600 700 800 900 1000 1100 1200 1300 700˚C 725˚C 764˚C 839˚C 650˚C 1278˚C Ra Ba Ca Mg Be Sr 1 22 | The Periodic Table Also called the boron group for its first member, this set of elements is also described as ‘triels’, because they can bond to a maximum of three other atoms. However, only the lighter ones do this; heavier members tend to bond to one other atom at a time. Boron is one of the hardest elements, but the metallic members are all quite soft. HEALTH EFFECTS – GOOD AND BAD Members of Group 3 have an impact on human health, and not always in a good way. • Boron: Although only needed in tiny amounts, this element is an essential nutrient in foods. It is used to help maintain strong bones. • Aluminium: This is non-toxic, and has no role in the body. Claims that aluminium is linked to dementia and cancer are now thought to be wrong. • Gallium: This metal is used as a last line of defence against the worst and most drug-resistant forms of malaria. • Indium: Large amounts of this metal will damage the kidneys. Metalworkers are most often exposed to this element. • Thallium: Tiny amounts of this metal cause vomiting and diarrhoea and as little as 15 milligrams will kill. It is reported that the CIA planned to poison Fidel Castro in 1959 by putting thallium salt, then used as a depilator, in his shoes. The idea – never carried out – was to make his iconic beard fall out. GROUP 3 From borax , an Arabic word that means ‘glistening white’. From alum, a mineral that has been used in dyeing since antiquity. From Gallia, a Latin term for France, the home country of the person who discovered it. From indigo, because the metal produces this colour of light when burned. From thallus , meaning ‘green shoot’, in reference to the colour of its flame. Named in 2016 after Nihon, the Japanese word for Japan. 113 Nh Nihonium 81 TI Thallium 49 In Indium 31 Ga Gallium 13 Al Aluminium 5 B Boron 1 3 1

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  Chemistry of Free Atoms and Particles

  • Kenneth Klabunde(Author)
  • 2012(Publication Date)
  • Academic Press

    (Publisher)

  CHAPTER Boron, Aluminum, Gallium, Indium, and Thallium (Group 1 1 1 A) I. Boron, Aluminum, Gallium, Indium, and Thallium Atoms (B, Al, Ga, In, TI) A. Occurrence, Properties, and Techniques These elements occur as atoms in nature or as telemers in stars, 1 and the more volatile of the group (Ga, In, TI) have been detected in the solar photo-sphere. And although the solar abundances of these and other elements have been reported, 2 whether their occurrence is as atoms, ions, or in chemical compounds is not clear. Pokhunkov 3 has reported the presence of Be, B, and M g O in small amounts in the upper atmosphere (100-210 km). Table 7 -1 4 -3 7 3 brings together some of the information pertaining to vaporiza-tion of these elements, particularly that found in the original literature. Vaporizations of these elements make for striking comparisons. Boron is distinctly different from the rest in that electron-beam vaporization is by far the preferred method, since a great deal of energy is needed to vaporize boron, and since molten boron is extremely corrosive. There have been numerous reports on the use of e-beam technology for boron vaporiza-t i o n 4 ' 6 ' 8 ' 1 0 and an apparatus avoiding high-voltage vacuum feedthroughs or water-cooled connections has been developed. 8 Laser evaporations of Β have also been successful 1 1 and mass spectrometry studies of the vapor formed showed the presence of B l 5 B 2 , and B 5 species. Arc vaporization and induction-heating vaporization of Β have also been reported. 5 , 7 A graphite crucible at 2350°C has also been employed for Β vaporization. 9 For chemical studies of Β vapor, e-beam vaporizations have been successfully em-ployed. 3 8 ' 3 9 Boron vapor is essentially monatomic, 1 2 although small amounts of B 2 1 4 and B 5 (from laser evaporation) 8 have been observed as mentioned above. The literature, is replete with reported methods for vaporizing aluminum.

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  The History and Use of Our Earth's Chemical Elements

  A Reference Guide

  • Robert E. Krebs(Author)
  • 2006(Publication Date)
  • Greenwood

    (Publisher)

  These families of related elements are called groups. The next several sections of this book present elements from the boron group (group 13; IIIA) through the noble gas group (group 18; VIII). The similarities and differences between the elements in each of these groups are not uniform and require some study in order to be understood in relation to the periodic table. Please note that names given to these groups in this book are not necessarily the same as used by some other references. Rather, they are descriptive as to their properties and characteristics. Not all elements in these groups have the same properties and characteristics. For instance, in group15, nitrogen is a gas, whereas the element just below it in group 15 is phosphorous, a non- metallic solid (semimetal). Just below phosphorous is arsenic (semimetal), followed by antimony and then bismuth, which are more metal-like. These last two, antimony and bismuth, are metals that might be considered an extension of periods 5 and 6 of the transition elements. Even though the elements listed in groups 13 (IIIA) to 18 (VIIIA) may not have the same properties and characteristics, they do have a distinct number of electrons in their outer valence shells related to their specific group. For instance, group 13 elements have three electrons in their outer valence shell, and group 14 elements have four electrons. Group 15 elements have five electrons in their outer valence shell, and group 16 elements have six elec- trons. The halogens in group 17 have seven electrons, and the inert elements in group 18 have a completed outer valence shell with eight electrons. At the end of each periods of group 18 (whose elements each have eight electrons in their respective outer valence shells), the table starts over with elements containing one electron in their respective valence shells (the alkali earth metals in group 1 [IA]).

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  Study Guide to Accompany Basics for Chemistry

  • Martha Mackin(Author)
  • 2012(Publication Date)
  • Academic Press

    (Publisher)

  B. The elements in a group have similar properties. C. Elements in the same group have the same number and arrangement of outermost electrons. 1. Group 1A elements are called alkali metals. ^ a) They have one electron in the outermost s orbital (s electron configuration). b) The elements are represented by a Lewis symbol with one dot. c) The number of filled inner energy levels increases as the atomic weights of the elements in the group increase (moving down in the group). 2. Group 2A elements are called alkaline earth metals and have two elec-2 trons in the outermost s orbital (s electron configuration). 2 1 3. Group 3A elements have an s ρ electron configuration in the outermost orbitals. 4. Group 4A orbitals Group 5A orbitals Group 6A the outermost orbitals 7. Group 7A elements outermost orbitals. 2 6 8. Group 8A elements (noble gases) have a s p configuration except for 2 helium which has a s configuration. D. For the main group elements, the group number is equal to the total number of outermost s and ρ electrons. III. Classification of the elements 5.4 Metals A. Metals are found on the left side of the zigzag line across the periodic table shown in Figure 5-6 in the textbook. B. Properties 1. They are solids at room temperature, except for mercury. 2 2 Group 4A elements have an s ρ electron configuration in the outermost 2 3 5. Group 5A elements have an s ρ electron configuration in the outermost 2 4 6. Group 6A elements (chalcogens) have a s p electron configuration in 2 5 Group 7A elements (halogens) have a s p electron configuration in the 78 Chapter Five. 2. They are shiny when polished and appear gray to white, except gold which is yellow and copper which is reddish. 3. They are malleable, meaning that they can be flattened by hammering or rolling. 4. They are ductile, meaning that they can be drawn into wires. 5. They are good conductors of heat and electricity.

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  Chemistry

  With Inorganic Qualitative Analysis

  • Therald Moeller(Author)
  • 2012(Publication Date)
  • Academic Press

    (Publisher)

  3+ . In its general chemical properties, boron resembles its diagonal neighbor silicon more than it resembles the other Group III elements. The remaining members of the group are metals and their compounds can be either ionic or covalent. The elements all form hydrates in aqueous solution.

  Down Representative Groups III–V: lower oxidation states become more stable

  Group IV

  C Si Ge Sn Pb

  Gallium, indium, and thallium can each have a + 1 oxidation state. However, compounds in the + 1 state are more numerous and more stable for indium and thallium than for gallium. This illustrates a general trend among the metals and semiconducting elements of Representative Groups III, IV, and V toward greater stability for lower oxidation states of the elements further down the groups.

  10.14 Representative Group IV

  In Representative Group IV carbon is a nonmetal, silicon and germanium are semiconducting elements, and tin and lead are metals. Atoms of these elements have ns 2 np 2 configurations in their valence shells.

  All of the members of this group exhibit an oxidation state of + 4, for example, in their compounds with the halogens and oxygen (EX4 and EO2 , where E is a Group IV element), and a state of -4 in the hydrides (EH4 ). There are substantial differences in the chemistry of the compounds of these elements. For the halides and hydrides, the one common factor is the tetrahedral molecular geometry, which is predicted by the electron-pair repulsion theory (Section 9.26 ). The general chemical stability of the halides and hydrides of this family is greatest for carbon and decreases from silicon to lead. For example, methane, CH4 , is not decomposed into its constituent elements below about 800°C, but the corresponding compounds of the other elements of this group decompose at much lower temperatures (decomposition temperatures: SiH4 , 450°C; GeH4 , 285°C; SnH4 , 150°C; PbH4 , about 0°C).

  The +2 oxidation state becomes increasingly stable down the carbon family. Carbon monoxide is the only stable compound of carbon in the +2 state. For silicon, the +2 state has been best characterized for the gases SiO and SiF2 , which can be obtained at high temperatures. The relatively few known compounds of dipositive germanium are potent reducing agents, the germanium being readily oxidized to the +4 state. The +2 oxidation state is most important in the chemistry of tin and lead, the metallic members of the family. These are the only members of the family that can form typical salts containing +2 ions. Such ions have the 18 + 2 configuration and result from the loss of the p

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  Chemistry

  Concepts and Problems, A Self-Teaching Guide

  • Richard Post, Chad Snyder, Clifford C. Houk(Authors)
  • 2020(Publication Date)
  • Jossey-Bass

    (Publisher)

  Nitrogen (N), a Group VA element, has ________ electrons in its outermost shell. Aluminum (Al), a Group IIIA element, has ____ electrons in its outermost shell.

  Answer: five; three

  The outer shell electrons are also known as valence electrons. The periodic table on the next page includes all of the symbols for the first 20 elements. The numbers of valence electrons are listed for lithium (Li), carbon (C), and argon (Ar). Fill in the number of valence electrons for each remaining element in this periodic table.

  Remember that helium (He) is an exception in Group VIIIA, since it only has a total of two electrons in its entire atom, both of which are valence electrons.

  Answer:

  The outer shell or valence electrons are especially important because those electrons are involved when atoms unite chemically to form compounds.

  When an atom of magnesium unites with another different atom to form a compound, what electrons of the magnesium atom are primarily involved?

  Answer: the two valence or outer shell electrons

  ELECTRON DOT SYMBOLS (LEWIS SYMBOLS)

  The outer shell or valence electrons may also be represented by a series of dots. Beryllium, with two valence electrons, can be represented as Be: (each dot represents one valence electron).

  represents a chlorine atom with how many valence electrons? ____

  Answer: seven

  The first 20 elements and their electron dot symbols are as follows.

  Note that some books represent boron as , aluminum as , carbon as , and silicon as . Such a representation is used to simplify the explanation of how many bonds a given element may have or may form with other elements, but it does not agree with the quantum mechanical concept of the atom (Chapter 1 ).

  We will discuss the number of bonds an element has in a compound in Chapter 14

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  Important Concepts and Applications of Atomic Physics and Quantum Chemistry

  • (Author)
  • 2014(Publication Date)
  • Learning Press

    (Publisher)

  Elements of the same period have the same number of electron shells; with each group across a period, the elements have one more proton and electron and become less metallic. This arrangement reflects the periodic recurrence of similar properties as the atomic number increases. For example, the alkaline metals lie in one group (group 1) and share similar properties, such as high reactivity and the tendency to lose one electron to arrive at a ________________________ WORLD TECHNOLOGIES ________________________ noble-gas electronic configuration. The periodic table of elements has a total of 109 elements. Modern quantum mechanics explains these periodic trends in properties in terms of electron shells. As atomic number increases, shells fill with electrons in approximately the order shown below. The filling of each shell corresponds to a row in the table. 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 7s 7p 8s In the s-block and p-block of the periodic table, elements within the same period gene-rally do not exhibit trends and similarities in properties (vertical trends down groups are more significant). However in the d-block, trends across periods become significant, and in the f-block elements show a high degree of similarity across periods (particularly the lanthanides). Periods Seven periods of elements occur naturally on Earth. For period 8, which includes elements which may be synthesized after 2010. A group in chemistry means a family of objects with similarities like different families. Chemical elements in the first period Group 1/17 2/18 # Name 1 H 2 He The first period contains fewer elements than any other, with only two, hydrogen and helium. They therefore do not follow the octet rule. Chemically, helium behaves as a noble gas, and thus is taken to be part of the group 18 elements. However, in terms of its nuclear structure it belongs to the s block, and is therefore sometimes classified as a group 2 element, or simultaneously both 2 and 18.

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  eBook - ePub

  Free Atoms, Clusters, and Nanoscale Particles

  • Kenneth J. Klabunde(Author)
  • 2012(Publication Date)
  • Academic Press

    (Publisher)

  Chapter 7

  Boron Group (Group 13)

  I Boron Group Atoms (B, Al, Ga, In, Tl)

  A Occurrence and Techniques

  The occurrence of these atoms in stars and the upper atmosphere (100–210 km) has been discussed, as have their vaporization characteristics.1 Elemental boron is strikingly more difficult to evaporate than Al, Ga, In, or Tl, and a variety of e -beam and laser techniques have been described. Recent reports have described a Xe–Cl pulsed excimer laser technique that works very well (301 nm, 50–90 mJ/pulse) for the evaporation of small amounts of boron.2−4 The importance of vapor-deposited Al films has been a driving force for the development of furnaces and crucibles that can contain corrosive molten aluminum.1 Crucibles of BN–TiB2 , BN, dense graphite, B4 C, AlN, and other refractory materials have been developed for this purpose. The other elements of the group are relatively easy to vaporize from normal W–Al2 O3 crucibles.

  Techniques for study of the chemistry of these atoms at temperatures ranging from 4 to 700 K have also been developed. These include high-temperature fast flow reactors (HTFFR)5 and the now familiar laser pulse/ flow system methods (see Chapter 2 ).

  A study of the vapors coming off of electromagnetically levitated and laser-heated Mo, W, Zr, and Al samples has been reported.6 Laser-induced fluorescence was used to probe atom concentrations and electronic states. Vaporization enthalpies were obtainable in some cases, and the authors discussed space-based applications of this method.

  Intriguing results coming from laser ablation of Al2 O3 have been reported. Laser-induced fluorescence was used to measure the energy distributions of Al atoms and Al/O molecules.7 The excimer laser power was held to a minimum to lower the effects of gas-phase collisions. Kinetic energies for both species were quite high, about 4 eV for Al and 1 eV for Al/O. Surprisingly, the AlO rotational and vibrational energies were quite low, corresponding to about 600 K. These results imply that laser evaporation/ablation is not a boil-off process but rather an electronic ablation mechanism. Related studies have been reported by Huie and Yeung.8

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