Chemistry
Group 4A
Group 4A refers to the elements in Group 14 of the periodic table, including carbon, silicon, germanium, tin, and lead. These elements share similar chemical properties, such as forming covalent compounds and exhibiting multiple oxidation states. They are important in various industrial applications, as well as in the fields of electronics, materials science, and environmental chemistry.
Written by Perlego with AI-assistance
Related key terms
1 of 5
8 Key excerpts on "Group 4A"
eBook - ePubEssentials of Inorganic Chemistry
For Students of Pharmacy, Pharmaceutical Sciences and Medicinal Chemistry
- Katja A. Strohfeldt(Author)
- 2015(Publication Date)
- Wiley(Publisher)
Chapter 5 The Carbon GroupMembers of group 14 of the periodic table (14th vertical column) are summarised as carbon group consisting of carbon (C), silicon (Si), germanium (Ge), tin (Sn) and lead (Pb) (Figure 5.1 ).Periodic table of elements; group 14 elements are highlightedFigure 5.1Group 14 elements have four valence shell electrons and therefore tend to form covalent compounds. Nevertheless, with increasing mass and atomic radius, the elements show increasingly more metallic characteristics and have lower melting and boiling points. Elements within this group show a graduation from nonmetallic elements (C) to elements that are classified as metals (Pb). Silicon is generally seen as nonmetallic, whereas germanium is metallic. Nevertheless, this classification is not definite. Silicon and germanium both form covalent diamond-type structures in the solid state, but their electrical behaviour indicates more a metallic behaviour. Therefore, silicon and germanium are classified as metalloids (see Chapter 4).Carbon is the essential element to life on earth, and the chemistry related to carbon is classified as organic chemistry and we will therefore not discuss it any further in this book. Organometallic chemistry relates to the interaction of carbon compounds with metals, and the basic concepts will be discussed in Chapter 8.Tin and lead have been under investigation for use as anticancer and antimicrobial agents, but so far with limited success. This chapter will discuss the pharmaceutical applications of silicon- and germanium-based drugs.5.1 General chemistry of group 14 elements
5.1.1 Occurrence, extraction and use of group 14 elements
Silicon is, after oxygen, the second most abundant element in the earth's crust. It occurs in a range of minerals and sand (SiO2 , quartz). In contrast, germanium, tin and lead are relatively rare elements, with tin and lead being extracted for thousands of years from their ores. The main source for tin is cassiterite (SnO2
eBook - PDF- Bernard Moody(Author)
- 2013(Publication Date)
- Arnold(Publisher)
20 Group IV: the carbon group Carbon, silicon, germanium, tin and lead 6 The notable general feature C about Group IV is the range 2,4 and gradation of the proper-14 ties shown by the elements Si and their compounds due to 2,8,4 the change in character of 32 the elements from weakly Ge electronegative to weakly !, 8,1 8,4 electropositive as the atomic 50 number increases. All show Sn a valency of 4 but with 2,8, 18,18,4 the progressive increase in 82 metallic character and Pb emergence of metallic 2,8,18,32,18,4 properties, there is a reduc-tion in valency by two, a pair of electrons remaining inert. The principal valency of carbon-tin inclusive is four while that of lead is two. Germanium and tin have a subsidiary valency of two, which is well defined, while the less stable valency state of lead is the group valency, four. In the naming of compounds, the higher valency used to be indicated by the suffix 4c and the lower by -ous. Germanium(n) and tin(n) compounds have a strong tendency to revert to the germanium(rv) and tin(iv) states, thereby undergoing oxidation. There-fore, they are strong reducing agents. Lead(iv) compounds, on the other hand, are oxidizing agents. Carbon is unique in forming compounds con-taining chains of carbon atoms, in which the covalent bonding is strong, the octet being com-plete with no unshared electron pairs and no tendency to form co-ionic bonds. This property is known as catenation. The systematic study of these compounds belongs to Organic Chemistry. Certain individual compounds of carbon are included here to illustrate family behaviour. In addition, miscel-laneous compounds of carbon which also contain nitrogen or oxygen as well as other elements and having no parallels elsewhere in the family are grouped at the end. Aspects of germanium are touched on very briefly where the gradation of chemical properties is well illustrated.
eBook - PDFEssentials of Inorganic Chemistry
For Students of Pharmacy, Pharmaceutical Sciences and Medicinal Chemistry
- Katja A. Strohfeldt(Author)
- 2014(Publication Date)
- Wiley(Publisher)
5 The Carbon Group Members of group 14 of the periodic table (14th vertical column) are summarised as carbon group consisting of carbon (C), silicon (Si), germanium (Ge), tin (Sn) and lead (Pb) (Figure 5.1). Group 14 elements have four valence shell electrons and therefore tend to form covalent compounds. Never- theless, with increasing mass and atomic radius, the elements show increasingly more metallic characteristics and have lower melting and boiling points. Elements within this group show a graduation from nonmetallic elements (C) to elements that are classified as metals (Pb). Silicon is generally seen as nonmetallic, whereas germanium is metallic. Nevertheless, this classification is not definite. Silicon and germanium both form covalent diamond-type structures in the solid state, but their electrical behaviour indicates more a metallic behaviour. Therefore, silicon and germanium are classified as metalloids (see Chapter 4). Carbon is the essential element to life on earth, and the chemistry related to carbon is classified as organic chemistry and we will therefore not discuss it any further in this book. Organometallic chemistry relates to the interaction of carbon compounds with metals, and the basic concepts will be discussed in Chapter 8. Tin and lead have been under investigation for use as anticancer and antimicrobial agents, but so far with limited success. This chapter will discuss the pharmaceutical applications of silicon- and germanium- based drugs. 5.1 General chemistry of group 14 elements 5.1.1 Occurrence, extraction and use of group 14 elements Silicon is, after oxygen, the second most abundant element in the earth’s crust. It occurs in a range of minerals and sand (SiO 2 , quartz). In contrast, germanium, tin and lead are relatively rare elements, with tin and lead being extracted for thousands of years from their ores. The main source for tin is cassiterite (SnO 2 ) and for lead galena (PbS).
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Research World(Publisher)
________________________ WORLD TECHNOLOGIES ________________________ Chapter- 12 Carbon Group (Group 14 Element) Group → 14 ↓ Period 2 6 C 3 14 Si 4 32 Ge 5 50 Sn 6 82 Pb 7 114 Uuq The carbon group is a periodic table group consisting of carbon ( C ), silicon ( Si ), germanium ( Ge ), tin ( Sn ), lead ( Pb ), and ununquadium ( Uuq ). In modern IUPAC notation, it is called Group 14 . In the old IUPAC and CAS systems, it was called Group IVB and Group IVA , respectively. In the field of semiconductor physics, it is still universally called Group IV . The group was once also known as the tetrels (from Greek tetra , four), stemming from the Roman numeral IV in the group ________________________ WORLD TECHNOLOGIES ________________________ names, or (not coincidentally) from the fact that these elements have four valence electrons (see below). Like other groups, the members of this family show patterns in its electron configuration, especially the outermost shells resulting in trends in chemical behavior: Z Element No. of electrons/shell 6 carbon 2, 4 14 silicon 2, 8, 4 32 germanium 2, 8, 18, 4 50 tin 2, 8, 18, 18, 4 82 lead 2, 8, 18, 32, 18, 4 114 ununquadium 2, 8, 18, 32, 32, 18, 4 Each of the elements in this group has 4 electrons in its outer energy level. The last orbital of all these elements is the p 2 orbital. In most cases, the elements share their electrons. The tendency to lose electrons increases as the size of the atom increases, as it does with increasing atomic number. Carbon alone forms negative ions, in the form of carbide (C 4− ) ions. Silicon and germanium, both metalloids, each can form +4 ions. Tin and lead both are metals while ununquadium is a synthetic short-lived radioactive metal. Tin and lead are both capable of forming +2 ions. Except for germanium and ununquadium, all of these elements are familiar in daily life either as the pure element or in the form of compounds.
eBook - PDF- Alina Kabata-Pendias(Author)
- 2010(Publication Date)
- CRC Press(Publisher)
333 19 Elements of Group 14 (Previously Group IVa) Trace elements of Group 14 are silicon (Si), germanium (Ge), tin (Sn), and lead (Pb). Geochemical properties and terrestrial abundance of these elements diverge widely. Their common characteris-tics are the weak solubility of their hydroxides and oxides in water and affinity to bond with oxygen. All elements have variable valences, + 2 and + 4 (Table 19.1), and only Si is a metalloid (nonmetal). Other elements of this group, Ge, Sn, and Pb, are metals and show chalcophilic properties in the terrestrial environment. SILICON I I NTRODUCTION A Silicon, especially in a combination with oxygen, is the basic nonmetallic components of all rocks and is considered as a trace element only in respect to its biochemical function. It is the second most abundant element in the lithosphere and comprises 25.7% (by weight) of the Earth’s crust. In the lithosphere it is the most stable element, preferable at + 4 oxidation state and occurs mainly as SiO 2 (Table 19.1). However, under specific conditions, it can be dissolved and transported, mainly in colloidal phase. Quartz, SiO 2 , is a very resistant mineral in all terrestrial compartments and is the basic compo-nent of all silicates (e.g., feldspar, quartz) and aluminum silicate minerals. Nonsilicate mineral containing Si is silicon carbide (carborundum), SiC. Due to versatile properties of Si, it is used in many different sectors of manufacture of some steels, aluminum alloys, glass, and refractory materials. Si is considered a semiconductor and thus it is an important commodity in the computer manufacturing business. Semiconductor-grade silicon is used in the manufacture of silicon chips and solar cells. It is also utilized in the production of ceramics, cements, papers, and textiles, as well as in several other productions, including insecti-cides, cosmetics, and pharmaceutics.
eBook - ePub- Kenneth J. Klabunde(Author)
- 2012(Publication Date)
- Academic Press(Publisher)
Chapter 8Carbon Group (Group 14)
I Carbon Group Atoms Vapors (C Si, Ge, Sn, Pb)
A Occurrence and Techniques
The vapors of these elements are intriguing, particularly carbon, where C1 , C2 , C3 , C4 , and C5 are all prevalent.1 Carbon as C1 , C2 , and C3 is important in astronomy as well as flames, and much of the original literature was reviewed earlier.1 As a brief summary, carbon has been vaporized (sublimed) in many ways including e -beam, laser, resistive heating, and the carbon arc. Very high temperatures are required and the ratios of C1 , C2 , C3 , C4 , and C5 can vary depending on the method used. However, C3 is generally the predominant species. Discussion of more recent innovations are given in Section IIA.Silicon behaves more like a metal during vaporization. It melts first, but unfortunately the melt is very corrosive and so e -beam methods are usually preferrable, although Knudsen cell, resistive heating and arc vaporizations have also been reported. The vapor composition is primarily Si atoms.Germanium, tin, and lead are relatively easy to vaporize and resistive heating from W–Al2 O3 crucibles works well. Monatomic species make up the vapor.B Physical Properties and Theoretical Studies
Collision quenching of electronically excited carbon atoms has been studied by Husain and Newton.2 They studied the 1 So(2p 2 ) state, which is 2.684 eve, above the triplet 3 Po state. Quenching by a variety of gases (He, H2 , N2 , Cl2 , CO, H2 O, CH4 , etc.) allowed comparisons of C(21 So) and Si(31 So) quenching absolute rate constants. Water and alkenes were among the most effective quenchers.C Chemistry
1 Abstraction, Insertion, and Addition Processes of Atoms
In earlier years a wealth of new chemistry resulted from the study of carbon atom abstraction of oxygen, hydrogen, halogen, etc.1 Recent work has dealt more with detailed mechanistic evaluations. For example, the mechanism of oxygen abstraction from THF by carbon atoms has been evaluated by ab initio theoretical methods.3 These calculations revealed a low-energy concerted pathway for three-bond cleavage to give the three product molecules directly. Thus, a biradical intermediate may not be involved in this interesting reaction, as was postulated earlier.4
No longer available |Learn more- (Author)
- 2014(Publication Date)
- Learning Press(Publisher)
Silicon dioxide is the principal constituent of sand. • Phosphorus (symbol P ) is a nonmetal essential to DNA. It is highly reactive, and as such is never found in nature as a free element. • Sulfur (symbol S ) is a nonmetal. It is found in two amino acids: cysteine and methionine. • Chlorine (symbol Cl ) is a halogen. It is used as a disinfectant, especially in swimming pools. • Argon (symbol Ar ) is a noble gas, making it almost entirely nonreactive. Incandescent lamps are often filled with noble gasses such as argon in order to preserve the filaments at high temperatures. Chemical elements in the fourth period Group 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Atomic number Name 19 K 20 Ca 21 Sc 22 Ti 23 V 24 Cr 25 Mn 26 Fe 27 Co 28 Ni 29 Cu 30 Zn 31 Ga 32 Ge 33 As 34 Se 35 Br 36 Kr electron configuration all begin with [Ar] 4s 1 4s 2 3d 1 4s 2 3d 2 4s 2 3d 3 4s 2 3d 5 4s 1 3d 5 4s 2 3d 6 4s 2 3d 7 4s 2 3d 8 4s 2 3d 10 4s 1 3d 10 4s 2 3d 10 4s 2 4p 1 3d 10 4s 2 4p 2 3d 10 4s 2 4p 3 3d 10 4s 2 4p 4 3d 10 4s 2 4p 5 3d 10 4s 2 4p 6 ________________________ WORLD TECHNOLOGIES ________________________ From left to right, aqueous solutions of: Co(NO 3 ) 2 (red); K 2 Cr 2 O 7 (orange); K 2 CrO 4 (yellow); NiCl 2 (green); CuSO 4 (blue); KMnO 4 (purple). Period 4 includes the biologically essential elements potassium and calcium, and is the first period in the d-block with the lighter transition metals. These include iron, the heaviest element forged in main-sequence stars and a principal component of the earth, as well as other important metals such as cobalt, nickle, copper, and zinc. Almost all have biological roles. Chemical elements in the fifth period Group 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 # Name 37 Rb 38 Sr 39 Y 40 Zr 41 Nb 42 Mo 43 Tc 44 Ru 45 Rh 46 Pd 47 Ag 48 Cd 49 In 50 Sn 51 Sb 52 Te 53 I 54 Xe Period 5 includes the important metals silver and tin and the biologically important element iodine.
eBook - PDFThe 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]).
Index pages curate the most relevant extracts from our library of academic textbooks. They’ve been created using an in-house natural language model (NLM), each adding context and meaning to key research topics.
