|Other metals in the periodic table|
Unknown chemical properties
|Atomic number color shows state at STP:
black=solid, green=Liquid, grey=unknown
In chemistry, other metals is a non-IUPAC-approved descriptive phrase for the metallic elements in Groups 13 to 16 of the periodic table. They are physically weak metals that show significant nonmetallic chemistry, consistent with their location between the 'true metals'[n 1] (to their left) and the metalloids (to their right). Among metals they are distinguished by having a combination of relatively low melting points (all less than 950 K) and relatively high electronegativity values (all more than 1.6, revised Pauling).
The descriptive phrase 'other metals' is used here as there is no accepted short-hand term for these metals. Occasionally, some or all of them have instead been referred to as B-subgroup metals, poor metals, or post transition metals; and by at least ten other alternative labels. All of these labels are surveyed later in this article.
Physically, they are soft (or brittle), mechanically weak metals with melting points lower than those of the transition metals; most also have boiling points lower than those of the transition metals. Being close to the metal-nonmetal border, their crystalline structures tend to show covalent or directional bonding effects, having generally greater complexity or fewer nearest neighbours than other metallic elements.[n 2]
Chemically, the other metals are characterised—to varying degrees—by covalent bonding tendencies, acid-base amphoterism and the formation of anionic species such as aluminates, stannates, and bismuthates (in the case of aluminium, tin, and bismuth, respectively). They can also form Zintl phases (half-metallic compounds formed between highly electropositive metals and moderately electronegative metals or metalloids).[n 3]
- 1 Applicable elements
- 2 Properties
- 3 Related groupings
- 4 Notes
- 5 Citations
- 6 References
'Other metals' is not an IUPAC-approved term. It is a descriptive phrase used here in view of the absence of a widely agreed collective term for the metals in question.[n 4] 'Other' in this sense has the related meanings of, 'Existing besides, or distinct from, that already mentioned'; 'auxiliary'; 'ancillary, secondary'. Some or all of these elements have sometimes instead been called B-subgroup metals, borderline metals, chemically weak metals, heavy metals (of low melting point), less typical metals, metametals, ordinary metals, p-block metals, peculiar metals, poor metals, post-transition metals,[n 5] semimetals (in the sense of metals with incomplete metallic character)[n 6] or transition metals. These classification groupings are generally found in the same region of the periodic table.
Elements falling into this loose category include aluminium, gallium, indium, thallium, tin, lead, bismuth and polonium. Germanium and antimony are occasionally included as other metals, although they are usually considered to be metalloids.[n 7] Elements 113–117, which are currently allocated the names ununtrium, ununtrium, flerovium, ununpentium, livermorium and ununseptium may be other metals; insufficient quantities of them have been synthesized to allow investigation of their actual physical and chemical properties.[n 8]
On the group 12 transition metals (zinc, cadmium and mercury), Smith observed that, 'Textbook writers have always found difficulty in dealing with these elements.' There is an abrupt and significant reduction in metallic character from group 11 to group 12. Their chemistry is that of main group elements. A 2003 survey of chemistry books showed that they were treated as either transition metals or main group elements on about a 50/50 basis.[n 9] The IUPAC Red Book notes that although the group 3−12 elements are commonly referred to as the transition elements, the group 12 elements are not always included. The group 12 elements do not satisfy the IUPAC Gold Book definition of a transition metal[n 10] (other than in the case of mercury at 4 K). They are included here only for comparative purposes.
- This section outlines relevant physical and chemical properties of the other metals. For complete profiles, including history, production, specific uses, and biological roles and precautions, see the main article for each element. Abbreviations: MH—Moh's hardness; BCN—bulk coordination number.[n 11]
Zinc is a soft metal (MH 2.5) with poor mechanical properties. It has a crystalline structure (BCN 6+6) that is slightly distorted from the ideal. Many zinc compounds are markedly covalent in character. The oxides of zinc in its preferred oxidation state of +2, namely ZnO and Zn(OH)2, are amphoteric; it forms anionic zincates in strongly basic solutions. Zinc forms Zintl phases such as LiZn, NaZn13 and BaZn13. Highly purified zinc, at room temperature, is ductile. It reacts with moist air to form a thin layer of carbonate that prevents further corrosion.
Cadmium is a soft, ductile metal (MH 2.0) that undergoes substantial deformation, under load, at room temperature. Like zinc, it has a crystalline structure (BCN 6+6) that is slightly distorted from the ideal. The halides of cadmium, with the exception of the fluoride, exhibit a substantially covalent nature. The oxides of cadmium in its preferred oxidation state of +2, namely CdO and CdOH2, are weakly amphoteric; it forms cadmates in strongly basic solutions. Cadmium forms Zintl phases such as LiCd, RbCd13 and CsCd13. When heated in air to a few hundred degrees, cadmium represents a toxicity hazard due to the release of cadmium vapour; when heated to its boiling point in air (just above 1000 K; 725 C; 1340 F; cf steel ~2700 K; 2425 C; 4400 F), the cadmium vapour oxidizes, 'with a reddish-yellow flame, dispersing as an aerosol of potentially lethal CdO particles.' Cadmium is otherwise stable in air and in water, at ambient conditions, protected by a layer of cadmium oxide.
Mercury is a liquid at room temperature. It has the weakest metallic bonding of all, as indicated by its bonding energy (61 kJ/mol) and melting point (−39 °C) which, together, are the lowest of all the metallic elements.[n 12] Solid mercury (MH 1.5) has a distorted crystalline structure, with mixed metallic-covalent bonding, and a BCN of 6. 'All of the [Group 12] metals, but especially mercury, tend to form covalent rather than ionic compounds.' The oxide of mercury in its preferred oxidation state (HgO; +2) is weakly amphoteric, as is the congener sulfide HgS. It forms anionic thiomercurates (such as Na2HgS2 and BaHgS3) in strongly basic solutions.[n 13] It forms or is a part of Zintl phases such as NaHg and K8In10Hg. Mercury is a relatively inert metal, showing little oxide formation at room temperature.
Aluminium in pure form is a soft metal (MH 3.0) with low mechanical strength. It has a close-packed structure (BCN 12) showing some evidence of partially directional bonding.[n 14] It has a low melting point (just over half that of steel) and a high thermal conductivity. Its strength is halved at 200 °C, and for many of its alloys is minimal at 300 °C. The latter three properties of aluminium limit its use to situations where fire protection is not required, or necessitate the provision of increased fire protection.[n 15] It bonds covalently in most of its compounds; has an amphoteric oxide; and can form anionic aluminates. Aluminium forms Zintl phases such as LiAl, Ca3Al2Sb6, and SrAl2. A thin protective layer of oxide confers a reasonable degree of corrosion resistance. It is susceptible to attack in low pH (<4) and high (> 8.5) pH conditions,[n 16] a phenomenon that is generally more pronounced in the case of commercial purity aluminium and aluminium alloys. Given many of these properties and its proximity to the dividing line between metals and nonmetals, aluminium is occasionally classified as a metalloid.[n 17] Despite its shortcomings, it has a good strength-to-weight ratio and excellent ductility; its mechanical strength can be improved considerably with the use of alloying additives; its very high thermal conductivity can be put to good use in heat sinks and heat exchangers; and it has a high electrical conductivity.[n 18] At lower temperatures, aluminium increases its deformation strength (as do most materials) whilst maintaining ductility (as do face-centred cubic metals generally). Chemically, bulk aluminium is a strongly electropositive metal, with a high negative electrode potential.[n 19]
Gallium is a soft, brittle metal (MH 1.5) that melts at only a few degrees above room temperature. It has an unusual crystalline structure featuring mixed metallic-covalent bonding and low symmetry (BCN 7 i.e. 1+2+2+2). It bonds covalently in most of its compounds, has an amphoteric oxide; and can form anionic gallates. Gallium forms Zintl phases such as Li2Ga7, K3Ga13 and YbGa2. It is slowly oxidized in moist air at ambient conditions; a protective film of oxide prevents further corrosion.
Indium is a soft, highly ductile metal (MH 1.0) with a low tensile strength. It has a partially distorted crystalline structure (BCN 4+8) associated with incompletely ionised atoms. The tendency of indium '...to form covalent compounds is one of the more important properties influencing its electrochemical behavior'. The oxides of indium in its preferred oxidation state of +3, namely In2O3 and In(OH)3 are weakly amphoteric; it forms anionic indates in strongly basic solutions. Indium forms Zintl phases such as LiIn, Na2In and Rb2In3. Indium does not oxidize in air at ambient conditions.
Thallium is a soft, reactive metal (MH 1.0), so much so that it has no structural uses. It has a close-packed crystalline structure (BCN 6+6) but an abnormally large interatomic distance that has been attributed to partial ionisation of the thallium atoms. Although compounds in the +1 (mostly ionic) oxidation state are the more numerous, thallium has an appreciable chemistry in the +3 (largely covalent) oxidation state, as seen in its chalcogenides and trihalides. It is the only one of the Group 13 elements to react with air at room temperature, slowly forming the amphoteric oxide Tl2O3. It forms anionic thallates such as Tl3TlO3, Na3Tl(OH)6, NaTlO2, and KTlO2, and is present as the Tl– thallide anion in the compound CsTl. Thallium forms Zintl phases, such as Na2Tl, Na2K21Tl19, CsTl and Sr5Tl3H.
Tin is a soft, exceptionally weak metal (MH 1.5);[n 20] a 1-cm thick rod will bend easily under mild finger pressure. It has an irregularly coordinated crystalline structure (BCN 4+2) associated with incompletely ionised atoms. All of the Group 14 elements form compounds in which they are in the +4, predominately covalent, oxidation state; even in the +2 oxidation state tin generally forms covalent bonds. The oxides of tin in its preferred oxidation state of +2, namely SnO and Sn(OH)2, are amphoteric; it forms stannites in strongly basic solutions. Below 13 °C; 55.4 F tin changes its structure and becomes 'grey tin', which has the same structure as diamond, silicon and germanium (BCN 4). This transformation causes ordinary tin to crumble and disintegrate since, as well as being brittle, grey tin occupies more volume due to having a less efficient crystalline packing structure. Tin forms Zintl phases such as Na4Sn, BaSn, K8Sn25 and Ca31Sn20. It has good corrosion resistance in air on account of forming a thin protective oxide layer. Pure tin has no structural uses. It is used in lead-free solders, and as a hardening agent in alloys of other metals, such as copper, lead, titanium and zinc.
Lead is a soft metal (MH 1.5) which, in many cases, is unable to support its own weight. It has a close-packed structure (BCN 12) but an abnormally large inter-atomic distance that has been attributed to partial ionisation of the lead atoms. It forms a semi-covalent dioxide PbO2; a covalently bonded sulfide PbS; covalently bonded halides; and a range of covalently bonded organolead compounds such as the lead(II) mercaptan Pb(SC2H5)2, lead tetra-acetate Pb(CH3CO2)4, and the once common, anti-knock additive, tetra-ethyl lead (CH3CH2)4Pb. The oxide of lead in its preferred oxidation state (PbO; +2) is amphoteric; it forms anionic plumbates in strongly basic solutions. Lead forms Zintl phases such as CsPb, Sr31Pb20, La5Pb3N and Yb3Pb20. It has reasonable to good corrosion resistance; in moist air it forms a mixed gray coating of oxide, carbonate and sulfate that hinders further oxidation.
Bismuth is a slightly radioactive, soft metal (MH 2.5) that is too brittle for any structural use. It has an open-packed crystalline structure (BCN 3+3) with bonding that is intermediate between metallic and covalent. For a metal, it has exceptionally low electrical and thermal conductivity. Most of the ordinary compounds of bismuth are covalent in nature. The oxide, Bi2O3 is predominately basic but will act as a weak acid in warm, very concentrated KOH. It can also be fused with potassium hydroxide in air, resulting in a brown mass of potassium bismuthate. The solution chemistry of bismuth is characterised by the formation of oxyanions; it forns anionic bismuthates in strongly basic solutions. Bismuth forms Zintl phases such as NaBi, Rb7In4Bi6 and Ba11Cd8Bi14. Bailar et al. refer to bismuth as being, 'the least "metallic" metal in its physical properties' given its brittle nature (and possibly) 'the lowest electrical conductivity of all metals.'[n 21]
Polonium is radioactive, soft metal with a hardness similar to lead. It has a simple cubic crystalline structure characterised (as determined by electron density calculations) by partially directional bonding, and a BCN of 6. Such a structure ordinarily results in very low ductility and fracture resistance however polonium has been predicted to be a ductile metal. It forms a covalent hydride; its halides are covalent, volatile compounds, resembling those of tellurium. The oxide of polonium in its preferred oxidation state (PoO2; +4) is predominately basic, but amphoteric if dissolved in concentrated aqueous alkali, or fused with potassium hydroxide in air. The yellow polonate(IV) ion PoO2−
3 is known in aqueous solutions of low Cl‒ concentration and high pH.[n 22] Polonides such as Na2Po, BePo, ZnPo, CdPo and HgPo feature Po2– anions; except for HgPo these are some of the more stable polonium compounds.[n 23]
Superficially, the B-subgroup metals are the metals in Groups IB to VIB of the periodic table, corresponding to Groups 11 to 16 using current IUPAC nonmenclature. Practically, the group 11 metals (copper, silver and gold) are ordinarily regarded as transition metals (or sometimes as coinage metals, or noble metals) whereas the group 12 metals (zinc, cadmium, and mercury) may or may not be treated as B-subgroup metals depending on if the transition metals are taken to end at group 11 or group 12. The 'B' nomenclature (as in Groups IB, IIB, and so on) was superseded in 1988 but is still occasionally encountered in more recent literature.[n 24]
The B-subgroup metals show nonmetallic properties; this is particularly apparent in moving from group 12 to group 16. Although the group 11 metals have normal close-packed metallic structures they show an overlap in chemical properties. In their +1 compounds (the stable state for silver; less so for copper) they are typical B-subgroup metals. In their +2 and +3 states their chemistry is typical of transition metal compounds.
Parish writes that, 'as anticipated', the borderline metals of groups 13 and 14 have non-standard structures. Gallium, indium, thallium, germanium, and tin are specifically mentioned in this context. The group 12 metals are also noted as having slightly distorted structures; this has been interpreted as evidence of weak directional (i.e. covalent) bonding.[n 25]
Chemically weak metals
Rayner-Canham and Overton use the term chemically weak metals to refer to the metals close to the metal-nonmetal borderline. These metals behave chemically more like the metalloids, particularly with respect to anionic species formation. The nine chemically weak metals identified by them are berylllium, aluminium, zinc, gallium, tin, lead, antimony, bismuth, and polonium.[n 26]
Heavy metals (of low melting point)
Van Wert grouped the periodic table metals into a. the light metals; b. the heavy brittle metals of high melting point, c. the heavy ductile metals of high melting point; d. the heavy metals of low melting point (Zn, Cd, Hg; Ga, In, Tl; Ge, Sn; As, Sb, Bi; and Po), and e. the strong, electropositive metals. Britton, Abbatiello and Robins speak of 'the soft, low melting point, heavy metals in columns lIB, IlIA, IVA, and VA of the periodic table, namely Zn, Cd, Hg; Al, Ga, In, Tl; [Si], Ge, Sn, Pb; and Bi. The Sargent-Welch Chart of the Elements groups the metals into: light metals, the lanthanide series; the actinide series; heavy metals (brittle); heavy metals (ductile); and heavy metals (low melting point): Zn, Cd, Hg, [Cn]; Al, Ga, In, Tl; Ge, Sn, Pb, [Fl]; Sb, Bi; and Po.[n 27]
Less typical metals
Habashi groups the elements into eight major categories:  typical metals (alkali metals, alkaline earth metals, and aluminium);  lanthanides (Ce–Lu);  actinides (Th–Lr);  transition metals (Sc, Y, La, Ac, groups 4–10);  less typical metals (groups 11–12, Ga, In, Tl, Sn and Pb);  metalloids (B, Si, Ge, As, Se, Sb, Te, Bi and Po);  covalent nonmetals (H, C, N, O, P, S and the halogens); and  monatomic nonmetals (that is, the noble gases).
The metametals are zinc, cadmium, mercury, indium, thallium, tin and lead. They are ductile elements but, compared to their metallic periodic table neighbours to the left, have lower melting points, relatively low electrical and thermal conductivities, and show distortions from close-packed forms. Sometimes beryllium and gallium are included as metametals despite having low ductility.
Abrikosov distinguishes between ordinary metals, and transition metals where the inner shells are not filled. The ordinary metals have lower melting points and cohesive energies than those of the transition metals. Gray identifies as ordinary metals: aluminium, gallium, indium, thallium, element 113, tin, lead, element 114, bismuth, element 115, and element 116. He adds that, 'in reality most of the metals that people think of as ordinary are in fact transition metals...'.
The p-block metals are the metals in groups 13‒15 (or 16) of the periodic table. Usually, this includes aluminium, gallium, indium and thallium; tin and lead; and bismuth. Germanium, antimony and polonium are sometimes also included, although the first two are commonly recognised as metalloids. The p-block metals tend to have structures that display low coordination numbers and directional bonding. Pronounced covalency is found in their compounds; the majority of their oxides are amphoteric.
Slater divides the metals 'fairly definitely, though not perfectly sharply' into the ordinary metals and the peculiar metals, the latter of which verge on the nonmetals. The peculiar metals occur towards the ends of the rows of the periodic table and include 'approximately:' gallium, indium, and thallium; carbon, silicon '(both of which have some metallic properties, though we have previously treated them as nonmetals),' germanium and tin; arsenic, antimony, and bismuth; and selenium '(which is partly metallic)' and tellurium. The ordinary metals have centro-symmetrical crystalline structures[n 28] whereas the peculiar metals have structures involving directional bonding. More recently, Joshua observed that the peculiar metals have mixed metallic-covalent bonding.
Farrell and Van Sicien use the term poor metal, for simplicity, 'to denote one with a significant covalent, or directional character.' Hill and Holman observe that, 'The term poor metals is not widely used, but it is a useful description for several metals including tin, lead and bismuth. These metals fall in a triangular block of the periodic table to the right of the transition metals. They are usually low in the activity (electrochemical) series and they have some resemblances to non-metals.' Reid et al. write that 'poor metals' is, '[A]n older term for metallic elements in Groups 13‒15 of the periodic table that are softer and have lower melting points than the metals traditionally used for tools.'
The term post-transition metal is generally used to describe the category of metallic elements in periods 4–6 of the periodic table, to the right of the transition elements. As this description excludes aluminium, a period 3 metal,[n 29] the post-transition elements thereby form a subset of the other metals. The post-transition metals generally show reduced electropositivity, anionic species formation and a capacity to combine with electropositive metals to give Zintl phases. Compounds of the group 12 metals (zinc, cadmium and mercury) are markedly non-ionic in character, both in structure and properties. Simple cationic chemistry in the group 14 metals, tin and lead, is the exception rather than the norm.
Which elements are counted as post-transition metals depends, in periodic table terms, on where the transition metals are taken to end.[n 30] In the 1950s, most inorganic chemistry textbooks defined transition elements as finishing at group 10 (nickel, palladium and platinum), therefore excluding group 11 (copper, silver and gold), and group 12 (zinc, cadmium and mercury). A survey of chemistry books in 2003 showed that the transition metals ended at either group 11 or group 12 with roughly equal frequency.
In modern use, the term 'semimetal' sometimes refers, loosely or explicitly, to metals with incomplete metallic character in crystalline structure, electrical conductivity or electronic structure. Examples include gallium, ytterbium, bismuth, mercury and neptunium. Metalloids, which are in-between elements that are neither metals nor nonmetals, are also sometimes instead called semimetals. The elements commonly recognised as metalloids are boron, silicon, germanium, arsenic, antimony and tellurium. In old chemistry, before the publication in 1789 of Lavoisier's 'revolutionary' Elementary Treatise on Chemistry, a semimetal was a metallic element with 'very imperfect ductility and malleability' such as zinc, mercury or bismuth.
Historically, the transition metal series 'includes those elements of the Periodic Table which "bridge the gap" between the very electropositive alkali and allkaline earth metals and the electronegative non-metals of the groups: nitrogen-phosphorus, oxygen-sulfur, and the halogens.' Cheronis, Parsons and Ronneberg wrote that, 'The transition metals of low melting point form a block in the Periodic Table: those of Groups II b [zinc, cadmium, mercury], III b [aluminium, gallium, indium, thallium], and germanium, tin and lead in Group IV. These metals all have melting points below 425 °C.'[n 31]
- The true metals comprise Group 11, the transition elements, including the 4f and 5f elements, and the typical members of Groups 1 and 2 (Wells 1985, pp. 1277, 1280).
- Most metals crystallise in close-packed structures with high bulk coordination numbers (8+ to 12, or higher). This is because total metallic bonding energy is optimised in the absence of interatomic gaps and increased when each atom has the greatest possible number of nearest-neighbour atoms. Most metals bordering the nonmetals have more complex structures, with lower bulk coordination numbers (4+ to 6+). This is attributed to the influence of a partial covalent bonding component in the crystal structures of these elements, which dictates fewer nearest neighbours.
- Zintl phases are usually metallic-looking brittle solids, with mixed ionic-covalent bonding, and are typically semiconductors or at least poor metallic conductors hence are sometimes described as semimetals or poor metals.
- 'Other metals' is also found as a category name for these elements, in the literature. Gray, however, has expressed the view that there should be a better name for these elements than 'other metals'.
- Aluminium sometimes is or is not counted as a post-transition metal.
- Examples include gallium and bismuth.
- Minor, junior or very rare metals. Sazhin, writing on the metallurgy of the rare and minor metals, classifies Hg, Sn, Sb and Bi as 'minor or junior metals', and Ga, In, Tl and Ge as 'very rare metals'. Further metals in this reference are classified as 'light rare metals'—Li, Rb, Cs • Be; rare earths—Sc, Y, lanthanides; 'high-melting rare metals'—Ti, Zr, Hf • V, Cb, Ta • Mo, Nd [sic], Re; and 'radioactive metals'—Ra and the actinides.
- Element 113 is expected to be able to form compounds involving the use of its d-orbital electrons; if this is borne out experimentally, then it would instead be categorized as a transition metal, albeit with significant other metal properties.
- The group 12 metals have been treated as transition metals for reasons of historical precedent, to compare and contrast properties, to preserve symmetry, or for basic teaching purposes.
- The IUPAC Gold Book defines a transition metal as 'An element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell.
- Moh's hardness values are taken from Samsanov, unless otherwise noted; bulk coordination number values are taken from Darken and Gurry, unless otherwise noted.
- Francium may have a comparably low bonding energy but its melting point of around 27°C is significantly higher than that of mercury, at −39°C.
- Mercury also forms partially anionic oxomercurates, such as Li2HgO2 and CdHgO4, by heating mixtures of HgO with the relevant cation oxides, including under oxygen pressure (Müller-Buschbaum 1995; Deiseroth 2004, pp. 173, 177, 185–186).
- The partially directional bonding in aluminium improves its shear strength but means that ultrahigh-purity aluminium cannot maintain work hardening at room temperature.
- Without the use of thermal insulation and detailed structural design attention, aluminium's low melting point and high thermal conductivity mitigate against its use, for example, in military ship construction—should a ship burn, the low melting point results in structural collapse; the high thermal conductivity helps spread the fire. Its use in the construction of cargo ships is limited as little or no economic advantage is gained over steel, once the cost and weight of fitting thermal insulation is taken into account.
- Aluminium can be attacked, for example, by alkaline detergents (including those used in dishwashers); by wet concrete, and by highly acidic foods such as tomatoes, rhubarb or cabbage. It is not attacked by nitric acid.
- See the list of metalloid lists for references
- Aluminium wire is used in electrical transmisson lines for the distribution of power but, on account of its low breaking strength, is refinforced with a central core of galvanised steel wire.
- In the absence of protective measures, the relatively high electropositivity of aluminium renders it susceptible to galvanic corrosion when in physical or electrical contact with other metals such as copper or steel, especially when exposed to saline media, such as sea water or wind-blown sea spray.
- Charles, Crane and Furness write that, 'Most metals, except perhaps lead and tin, can be alloyed to give [yield] strengths that lie in the upper two-thirds of the low-strength range…'
- Which metal has the lowest electrical conductivity is debatable but bismuth is certainly in the lowest cohort; Hoffman refers to bismuth as 'a poor metal, on the verge of being a semiconductor.'
- Bagnall writes that the fusion of polonium dioxide with a potassium chlorate/hydroxide mixture yields a bluish solid which, '...presumably contains some potassium polonate.'
- Bagnall noted that the rare-earth polonides have the greatest thermal stability of any polonium compound.
- Greenwood and Earnshaw refer to the B-subgroup metals as post-transition elements: 'Arsenic and antimony are classed as metalloids or semi-metals and bismuth is a typical B sub-group (post-transition-element) metal like tin and lead.'
- Aluminium is identified by Parish, along with germanium, antimony and bismuth, as being a metal on the boundary line between metals and non-metals; he suggests that all these elements are 'probably better classed as metalloids.'
- Pauling, in contrast, refers to the strong metals in Groups 1 and 2 (that form ionic compounds with 'the strong nonmetals in the upper right corner of the periodic table.').
- Hawkes, attempting to address the question of what is a heavy metal, commented that, 'Being a heavy metal has little to do with density, but rather concerns chemical properties'. He observed that, 'It may mean different things to different people, but as I have used, heard and interpreted the term over the last half-century, it refers to metals with insoluble sulfides and hydroxides, whose salts produce colored solutions in water, and whose complexes are usually colored.' He goes on to note that, 'The metals I have seen referred to as heavy metals comprise a block of all the metals in Groups 3 to 16 that are in periods 4 and greater. It may also be stated as the transition metals and post-transition metals.
- On manganese, Slater says, '[It] is a very peculiar and anomalous exception to the general order of the elements. It is the only definite metal, far from the nonmetals in the table, which has a complicated structure.'
- Aluminium is sometimes referred to as a pre-transition metal, along with the group 1 alkali metals and group 2 alkaline earth metals.
- A first IUPAC definition states "[T]he elements of groups 3–12 are the d-block elements. These elements are also commonly referred to as the transition elements, though the elements of group 12 are not always included". Depending on the inclusion of group 12 as transition metals, the post-transition metals therefore may or may not include the group 12 elements—zinc, cadmium, and mercury. A second IUPAC definition for transition metals states "An element whose atom has an incomplete d sub-shell, or which can give rise to cations with an incomplete d sub-shell." Based on this definition one could argue group 12 should be split with mercury and copernicium as transition metals, and zinc and cadmium as post-transition metals. Of relevance is the synthesis of mercury(IV) fluoride, which seemingly establishes mercury as a transition metal. This conclusion has been challenged by Jensen with the argument that HgF4 only exists under highly atypical non-equilibrium conditions (at 4° K) and should best be considered as an exception. Copernicium is predicted to have (a) an electron configuration similar to that of mercury; and (b) a predominance of its chemistry in the +4 state, and on that basis would be regarded as a transition metal.
- In fact, both aluminium (660.32) and germanium (938.25) have melting points greater than 425°C.
- Russell & Lee 2005, p. 5
- Benbow 2008, p. 45; Gupta U 2010, p. 49
- Müller 1992, p. 123
- Evers 2011, p. 58
- Kauzlarich 2005, pp. 6006
- Häussermann 2008, p. 628
- Kauzlarich, Payne & Webb, pp. 45–46, 59
- Taylor et al. 2007, p. 148; Rankin 2011, p. 388
- Gray 2010
- Oxford English Dictionary 1989, 'other'
- Roget's 21st Century Thesaurus
- Massalski 1986, p. 346: Massalski distinguishes between the noble metals (Cu, Ag and Au), and the 'B subgroup metals', to the right of the noble metals in the periodic table.
- Stott 1956, pp. 99–106; 107; Rayner-Canham & Overton 2006, pp. 29–30: 'There is a subgroup of metals, those closest to the borderline, that exhibit some chemical behaviour that is more typical of the semimetals, particularly formation of anionic species. These nine chemically weak metals are beryllium, aluminium, zinc, gallium, tin, lead, antimony, bismuth, and polonium.'
- Parish 1977, pp. 178–199
- Whitten et al. 2007, p. 868; Cox 2004, p. 185
- Whitten et al. 2007, p. 868
- Cox 2004, p. 185
- Pashaey & Seleznev 1973, p. 565; Gladyshev & Kovaleva 1998, p. 1445; Eason 2007, p. 294
- Jezequel & Thomas 1997, pp. 6620–6
- Sazhin 1961
- Smith 1990, p. 113
- Sorensen 1991, p. 3
- King 1995, pp. xiii, 273–288; Cotton et al. 1999, pp. ix, 598; Massey 2000, pp. 159–176
- Jensen 2003, p. 952
- Young et al. 1969; Geffner 1969; Jensen 2003
- IUPAC 2005, p. 51
- Crichton 2012, p. 11
- IUPAC 2006–, transition element entry
- Yousif 2007, p. 11; Rosca et al. 2009, pp. 2235–36; Kown et al. 2013
- Samsanov 1968
- Darken & Gurry 1953, pp. 50–53
- Schweitzer 2003, p. 603
- Hutchinson 1964, p. 562
- Greenwood & Earnshaw 1998, p. 1209; Gupta CK 2002, p. 590
- Rayner-Canham & Overton 2006, p. 30
- Kneip 1996, p. xxii
- Russell & Lee 2005, p. 339
- Sequeira 2013, p. 243
- Russell & Lee 2005, p. 349
- Borsari 2005, p. 608
- Dirkse 1986, pp. 287–288, 296; Ivanov-Emin, Misel'son & Greksa 1960
- Wanamaker & Pennington 1921, p. 56
- Rayner-Canham 2006, p. 570; Chambers & Holliday 1975, p. 58; Wiberg, Holleman & Wiberg 2001, p. 247; Aylward & Findlay 2008, p. 4
- Poole 2004, p. 821
- Mittemeijer 2010, p. 138
- Russell & Lee 2005, pp. 1–2; 354
- Rayner-Canham 2006, p. 567
- Moeller 1952, pp. 859, 866
- Cooney & Hall 1966, p. 2179
- Deiseroth 2008, pp. 179‒180; Sevov 1993
- Russell & Lee 2005, p. 354
- Gerard & King 1968, p. 16; Dwight 1999, p. 2
- Russell & Lee 2005, pp. 1–2; 359
- Ogata, Li & Yip 2002; Russell & Lee 2005, p. 360; Glaeser 1992, p. 224
- Lyons 2004, p. 170
- Cobb 2009, p. 323
- Polemear 2006, p. 184
- Holl 1989, p. 90
- Ramroth 2006, p. 6; US Dept. of Transportation, Maritime Administration 1987, pp. 97, 358
- Noble 1985, p. 21
- Cooper 1968, p. 25; Henderson 2000, p. 5
- Kauzlarich 2005, pp. 6009–10
- Dennis & Such 1993, p. 391
- Cramer & Covino 2006, p. 25
- Hinton & Dobrota 1978, p. 37
- Holman & Stone 2001, p. 141
- Hurd 2005, p. 4-15
- Vargel 2004, p. 580
- Hill & Holman 2000, p. 276
- Russell & Lee 2005, p. 360
- Clegg & Dovaston 2003, p. 5/5
- Liptrot 2001, p. 181
- Kent 1993, pp. 13–14
- Steele 1966, p. 60
- Davis 1999, p. 75–7
- Russell & Lee 2005, p. 387
- Driess 2004, p. 151; Donohue 1982, p. 237
- Walker, Enache & Newman 2013, p. 38
- Atkins et al. 2006, p. 123
- Corbett 1996, p. 161
- Eranna 2012, p. 67
- Chandler 1998, p. 59
- Russell & Lee 2005, p. 389
- Evans 1966, p. 129–130
- Liang, King & White 1968, p. 288
- Busev 1962, p. 33; Liang, King & White 1968, p. 287; Solov'eva et al. 1973, p. 43; Greenwood & Earnshaw 1998, p. 226; Leman & Barron 2005, p. 1522
- Kneip 1996, p. xxii; Corbett 1996, pp. 153, 158
- Russell & Lee 2005, p. 390
- Wells 1985, p. 1279–80
- Howe 1968a, p. 709; Taylor & Brothers 1993, p. 131; Lidin 1996, p. 410; Tóth & Győri 2005, pp. 4, 6–7
- Chambers & Holliday 1975, p. 144
- Bashilova & Khomutova 1984, p. 1546
- Ropp 2012, p. 484
- King & Schleyer 2004, p. 19
- Corbett 1996, p. 153; King 2004, p. 199
- Russell & Lee 2005, p. 405
- Charles, Crane & Furness 1997, pp. 49, 57
- Rayner-Canham 2006, pp. 306, 340
- Wiberg, Holleman & Wiberg 2001, p. 247
- Corbett 1996, p. 143; Cotton et al. 1999, pp. 99, 122; Kauzlarich 2005, p. 6009
- Russell & Lee 2005, pp. 402, 405
- Russell & Lee 2005, p. 402, 407
- Alhassan & Goodwin 2005, p. 532
- Schweitzer 2003, p. 695
- Mackay & Mackay 1989, p. 86; Norman 1997, p. 36
- Hutchinson 1959, p. 455; Wells 1984, p. 1188; Liu, Knowles & Chang 1995, p. 125; Bharara & Atwood 2005, pp. 2, 4
- Durrant & Durrant 1970, p. 670; Lister 1998, p. A12; Cox 2004, p. 204
- Patnaik 2003, p. 474
- Corbett 1996, pp. 143, 147; Cotton et al. 1999, p. 122; Kauzlarich 2005, p. 6009
- Russell & Lee 2005, pp. 411, 13
- Russell & Lee 2005, p. 428
- Eagleson 1994, p. 282
- Russell & Lee 2005, p. 427
- Sidgwick 1937, p. 181
- Howe 1968, p. 62
- Durrant & Durrant 1970, p. 790
- Wiberg, Holleman & Wiberg 2001, p. 771; McQuarrie, Rock & Gallogly 2010, p. 111
- Ropp 2012, p. 328
- Miller, Lee & Choe 2002, p. 14; Aleandri & Bogdanović 2008, p. 326
- Bobev & Sevov 2002
- Xia & Bobev 2006
- Bailar et al. 1984, p. 951
- Hoffman 2004
- Beamer & Maxwell 1946, pp. 1, 31
- Russell & Lee 2005, p. 431
- Halford 2006,p. 378
- Legut, Friák & Šob 2010
- Wiberg, Holleman & Wiberg 2001, pp. 594; Petrii 2012, p. 754
- Bagnall 1966, p. 83
- Bagnall 1966, pp. 42, 61; Wiberg, Holleman & Wiberg 2001, pp. 767–68
- Schwietzer & Pesterfield pp. 241, 243
- Bagnall 1962, p. 211
- Wiberg, Holleman & Wiberg 2001, pp. 283, 595
- Greenwood & Earnshaw 1998, p. 766
- Bagnall 1966, p. 47
- Zubieta & Zuckerman 2009, p. 260: 'The compounds AsSn and SbSn, which are classified as alloys of two B subgroup metals, exhibit superconducting properties with a transition temperature of about 4 K.'; Schwartz 2010, p. 32: 'The metals include the alkali and alkaline earths, beryllium, magnesium, copper, silver, gold and the transition metals. These metals exhibit those characteristics generally associated with the metallic state. The B subgroups comprise the remaining metallic elements. These elements exhibit complex structures and significant departures from typically metallic properties. Aluminum, although considered under the B subgroup metals, is somewhat anomalous as it exhibits many characteristics of a true metal.'
- Greenwood & Earnshaw 1998, p. 548
- Phillips & Williams 1965, pp. 4‒5; Steele 1966, p. 66
- Phillips & Williams 1965, p. 33
- Wiberg, Holleman & Wiberg 2001, pp. 1253, 1268
- Steele 1966, p. 67
- Parish 1977, pp. 201–202
- Parish 1977, pp. 178
- Rayner-Canham & Overton 2006, p. 29‒30
- Pauling 1988, p. 173
- Van Wert 1936, pp. 16, 18
- Britton, Abbatiello & Robins 1972, p. 704
- Sargent-Welch 2008
- Hawkes 1997
- Habashi 2010
- Wiberg, Holleman & Wiberg 2001, p. 143
- Klemm 1950
- Miller GJ, Lee C & Choe W 2002, p. 22
- Abrikosov 1988, p. 31
- Cremer 1965, p. 514
- Gray 2009, p. 9
- Parish 1977, pp. 178, 189–190, 192–3
- Slater 1939, p.&npsb;444‒445
- Slater 1939, p. 448
- Joshua 1991, p. 45
- Farrell & Van Sicien 2007, p. 1442
- Hill & Holman 2000, p. 40
- Reid 2011, p. 143
- Cox 2004, pp. 27, 112, 185, 196, 202–3
- Jensen 2008
- Johansen & Mackintosh 1970, pp. 121–4; Divakar, Mohan & Singh 1984, p. 2337; Dávila et al. 2002, p. 035411-3
- Savitsky 1961, p. 107
- Hindman 1968, p. 434: 'The high values obtained for the [electrical] resistivity indicate that the metallic properties of neptunium are closer to the semimetals than the true metals. This is also true for other metals in the actinide series.'; Dunlap et al. 1970, pp. 44, 46: '...α-Np is a semimetal, in which covalency effects are believed to also be of importance...For a semimetal having strong covalent bonding, like α-Np...'
- Strathern 2000, p. 239
- Roscoe & Schormlemmer 1894, p. 4
- Murray 1809, p. 300
- Young et al. 1969, p. 228
- Cheronis, Parsons & Ronneberg 1942, p. 570
- Abrikosov AA 1988, Fundamentals of the theory of metals, North Holland, Amsterdam, ISBN 0444870946
- Aleandri LE & Bogdanović B 2008, 'The magnesium route to active metals and intermetallics, in A Fürstner (ed.), Active metals: Preparation, characterization, applications, VCH Verlagsgesellschalt, Weinheim, ISBN 3527292071, pp. 299‒338
- Alhassan SJ & Goodwin FE 2005, Lead and Alloys, in R Baboian (ed), 'Corrosion Tests and Standards: Application and Interpretation,' 2nd ed., ASTM International, West Conshohocken, PA, pp. 531–6, ISBN 0803120982
- Atkins P, Overton T, Rourke J, Weller M & Armstrong F 2006, Shriver & Atkins inorganic chemistry, 4th ed., Oxford University Press, Oxford, ISBN 9780199264636
- Aylward G & Findlay T 2008, SI chemical data, 6th ed., John Wiley, Milton, Queensland, ISBN 9780470816387
- Bagnall KW 1962, 'The chemistry of polonium,' in HHJ Emeleus & AG Sharpe (eds), Advances in inorganic chemistry and radiochemistry, vol. 4, Academic Press, New York, pp. 197‒230
- Bagnall KW 1966, The chemistry of selenium, tellurium and polonium, Elsevier, Amsterdam
- Bailar JC, Moeller T, Kleinberg J, Guss CO, Castellion ME & Metz C 1984, Chemistry, 2nd ed., Academic Press, Orlando, ISBN 0120728559
- Bashilova NI & Khomutova, TV 1984, 'Thallates of alkali metals and monovalent thallium formed in aqueous solutions of their hydroxides', Russian Chemical Bulletin, vol. 33, no. 8, August, pp. 1543–47
- Benbow EM 2008, From paramagnetism to spin glasses: Magnetic studies of single crystal intermetallics, PhD dissertation, Florida State University
- Bharara MS & Atwood, DA 2005, 'Lead: Inorganic chemistry', Encyclopedia of inorganic chemistry, RB King (ed.), 2nd ed., John Wiley & Sons, New York, ISBN 9780470860786
- Beamer WH & Maxwell CR 1946, Physical properties and crystal structure of polonium, Los Alamos Scientific Laboratory, Oak Ridge, Tennessee
- Bobev S & Sevov SC 2002, 'Five ternary Zintl phases in the systems alkali-metal–indium–bismuth', Journal of Solid State Chemistry, vol. 163, no. 2, pp. 436–448, doi:10.1006/jssc.2001.9423
- Borsai, M 2005, 'Cadmium: Inorganic & coordination chemistry', in RB King (ed.), Encyclopedia of inorganic chemistry, 2nd ed., vol. 2, John Wiley & Sons, New York, pp. 603–19, ISBN 9780470860786
- Britton RB, Abbatiello FJ & Robins KE 1972, 'Flux pumps and superconducting components, in Y Winterbottom (ed.), Proceedings of the 4th International Conference on Magnetic Technology, 19‒22 September 1972, Upton, New York, Atomic Energy Commission, Washington DC, pp. 703‒708
- Busev, AI 1962, The analytical chemistry of indium, Pergamon, Oxford
- Chambers C & Holliday AK 1975, Modern inorganic chemistry: An intermediate text, Butterworths, London, ISBN 0408706635
- Chandler H 1998, Metallurgy for the non-metallurgist, ASM International, Materials Park, Ohio, ISBN 0871706520
- Charles JA, Crane FAA & Furness JAG 1997, Selection and use of Engineering Materials, 3rd ed., Butterworth-Heinemann, Oxford, ISBN 0750632771
- Cheronis ND, Parsons JB & Ronneberg CE 1942, The study of the physical world, Houghton Mifflin Company, Boston
- Clegg AG & Dovaston NG 2003, 'Conductors and superconductors', in MA Laughton & DF Warne, Electrical engineer's reference book, 16th ed., Elsevier Science, Oxford, pp. 5/1–13, ISBN 0750646373
- Cobb F 2009, Structural engineer's pocket book, 2nd ed., Elsevier, Oxford, ISBN 9780750686860
- Cooney RPJ & Hall JR 1966, 'Raman spectrum of thiomercurate(II) ion,' Australian Journal of Chemistry, vol. 19, pp. 2179–2180
- Cooper DG 1968, The periodic table, 4th ed., Butterworths, London
- Corbett JD 1996, 'Zintl phases of the early p-block elements', in SM Kauzlarich (ed.), Chemistry, structure and bonding of Zintl phases and ions, VCH, New York, ISBN 1560819006, pp. 139‒182
- Cotton FA, Wilkinson G, Murillo CA & Bochmann M 1999, Advanced inorganic chemistry, 6th ed., John Wiley & Sons, New York, ISBN 9780471199571
- Cox PA 2004, Inorganic chemistry, 2nd ed., Instant notes series, Bios Scientific, London, ISBN 1859962890
- Cramer SD & Covino BS 2006, Corrosion: environments and industries, ASM Handbook, vol. 13C, ASM International, Metals Park, Ohio, ISBN 0871707098
- Cremer HW, Davies TR, Watkins SB 1965, Chemical Engineering Practice, vol. 8, 'Chemical kinetics,' Butterworths Scientific Publications, London
- Crichton R 2012, Biological inorganic chemistry: A new introduction to molecular structure and function, 2nd ed., Elsevier, Amsterdam, ISBN 9780444537829
- Dennis JK & Such TE 1993, Nickel and chromium plating, 3rd ed, Woodhead Publishing, Abington, Cambridge, ISBN 1855730812
- Darken L & Gurry R 1953, Physical chemistry of metals, international student edition, McGraw-Hill Book Company, New York
- Dávila ME, Molotov SL, Laubschat C & Asensio MC 2002, 'Structural determination of Yb single-crystal films grown on W(110) using photoelectron diffraction', Physical Review B, vol. 66, no. 3, p. 035411–18, doi:10.1103/PhysRevB.66.035411
- Davis JR (ed.) 1999, 'Galvanic, deposition, and stray-current deposition', Corrosion of aluminum and aluminum alloys, ASM International, Metals Park, Ohio, pp. 75–84, ISBN 0871706296
- Deiseroth H-J 2008, 'Discrete and extended metal clusters in alloys with mercury and other Group 12 elements', in M Driess & H Nöth (eds), Molecular clusters of the main group elements, Wiley-VCH, Chichester, pp. 169‒187, ISBN 9783527614370
- Dirkse, TP (ed.) 1986, Copper, silver, gold and zinc, cadmium, mercury oxides and hydroxides, IUPAC solublity data series, vol. 23, Pergamon, Oxford, ISBN 0080324975
- Divakar C, Mohan M & Singh AK 1984, 'The kinetics of pressure-induced fcc-bcc transformation in ytterbium', Journal of Applied Physics, vol. 56, no. 8, pp. 2337–40, doi:10.1063/1.334270
- Donohue J 1982, The structures of the elements, Robert E. Krieger, Malabar, Florida, ISBN 0898742307
- Driess M & Nöth H 2004, Molecular clusters of the main group elements, Wiley-VCH, Weinheim
- Dunlap BD, Brodsky MB, Shenoy GK & Kalvius GM 1970, 'Hyperfine interactions and anisotropic lattice vibrations of 237Np in α-Np metal', Physical Review B, vol. 1, no. 1, pp. 44–49, doi:10.1103/PhysRevB.1.44
- Durrant PJ & Durrant B 1970, Introduction to advanced inorganic chemistry, 2nd ed., Longman
- Dwight J 1999, Aluminium design and construction, E & FN Spon, London, ISBN 0419157107
- Eagleson M 1994, Concise encyclopedia chemistry, Walter de Gruyter, Berlin, ISBN 3110114518
- Eason R 2007, Pulsed laser deposition of thin films: applications-led growth of functional materials, Wiley-Interscience, New York
- Eranna G 2012, Metal oxide nanostructures as gas sensing devices, CRC Press, Boca Raton, Florida, ISBN 9781439863404
- Evans RC 1966, An introduction to crystal chemistry, 2nd (corrected) edition, Cambridge University Press, London
- Evers J 2011, 'High pressure investigations on AIBIII Zintl compounds (AI = Li to Cs; BIII = Al to Tl) up to 30 Gpa', in TF Fässler (ed.), Zintl phases: Principles and recent developments, Springer-Verlag, Berlin, pp. 57‒96, ISBN 9783642211508
- Farrell HH & Van Sicien CD 2007, 'Binding energy, vapor pressure, and melting point of semiconductor nanoparticles', Journal of Vacuum Science Technology B, vol. 25, no. 4, pp. 1441–47, doi:10.1116/1.2748415
- Geffner SL 1969, 'Teaching the transition elements', letter, Journal of Chemical Education, vol. 46, no. 5, p. 329, doi:10.1021/ed046p329.4
- Gerard G & King WR 1968, 'Aluminum', in CA Hampel (ed.), The encyclopedia of the chemical elements, Reinhold, New York
- Gladyshev VP & Kovaleva SV 1998, 'Liquidus shape of the mercury–gallium system', Russian Journal of Inorganic Chemistry, vol. 43, no. 9, pp. 1445–
- Glaeser WA 1992, Materials for tribology, Elsevier Science, Amsterdam, ISBN 0444884955
- Gray T 2009, The elements: A visual exploration of every known atom in the universe, Black Dog & Leventhal, New York, ISBN 9781579128142
- Gray T 2010, 'Other Metals (11)', viewed 27 September 2013
- Greenwood NN & Earnshaw A 1998, Chemistry of the elements, 2nd ed., Butterworth-Heinemann, ISBN 0750633654
- Gupta CK 2002, Chemical metallurgy: Principles and practice, Wiley-VCH, Weinheim, ISBN 3527303766
- Gupta U 2010, Design and characterization of post-transition, main-group, heteroatomic clusters using mass spectrometry, anion photoelectron spectroscopy and velocity map imaging, PhD dissertation, Pennsylvania State University
- Habashi F 2010, 'Metals: Typical and less typical, transition and less typical', Foundations of Chenistry, vol. 12, pp. 31–39, doi:10.1007s10698-009-9069-6
- Halford GR 2006, Fatigue and durability of structural materials, ASM International, Materials Park, Ohio, ISBN 0871708256
- Häussermann U 2008, 'Coexistence of hydrogen and polyanions in multinary main group element hydrides', Zeitschrift für Kristallographie - Crystalline Materials, vol. 223, no. 10, pp. 628–635, doi:10.1524/zkri.2008.1016
- Hawkes SJ 1997, 'What is a "Heavy Metal"?', Journal of Chemical Education, vol. 74, no. 11, p,&nsbp;1374, doi:10.1021/ed074p1374
- Henderson M 2000, Main group chemistry, The Royal Society of Chemistry, Cambridge, ISBN 0854046178
- Hill G & Holman J 2000, Chemistry in context, 5th ed., Nelson Thornes, Cheltenham, ISBN 0174483074
- Hindman JC 1968, 'Neptunium', in CA Hampel (ed.), The encyclopedia of the chemical elements, Reinhold, New York, pp. 432–7
- Hinton H & Dobrota N 1978, 'Density gradient centrifugation', in TS Work & E Work (eds), Laboratory techniques in biochemistry and molecular biology, vol. 6, Elsevier/North-Holland Biomedical Press, Amsterdam, pp. 1–290, ISBN 0720442001
- Hoffman P 2004, Semimetal surfaces, viewed 17 September 2013.
- Holl HA 1989, 'Materials for warship applications – past, present and future', in R Bufton & P Yakimiuk (eds), Past, present and future engineering in the Royal Navy, the Institute of Marine Engineers centenary year conference proceedings, RNEC Manadon, Plymouth, 6‒8 September 1989, Marine Management (Holdings) for the Institute of Marine Engineers, London, pp. 87–96, ISBN 090720628X
- Holman J & Stone P 2001, Chemistry, 2nd ed., Nelson Thornes, Walton on Thames, ISBN 0748762396
- Howe, HE 1968, 'Bismuth' in CA Hampel (ed.), The encyclopedia of the chemical elements, Reinhold, New York, pp. 56–65
- Howe, HE 1968a, 'Thallium' in CA Hampel (ed.), The encyclopedia of the chemical elements, Reinhold, New York, pp. 706–711
- Hurd MK 1965, Formwork for concrete, 7th ed, American Concrete Institute, Farmington Hills, Michigan, ISBN 0870311778
- Hutchinson E 1964, Chemistry: The elements and their reactions, 2nd ed., W B Saunders Company, Philadelphia
- IUPAC 2005, Nomenclature of inorganic chemistry (the "Red Book"), NG Connelly & T Damhus eds, RSC Publishing, Cambridge, ISBN 0854044388
- IUPAC 2006–, Compendium of chemical terminology (the "Gold Book"), 2nd ed., by M Nic, J Jirat & B Kosata, with updates compiled by A Jenkins, ISBN 0967855098, doi:10.1351/goldbook
- Ivanov-Emin BN, Nisel'son LA & Greksa, Y 1960, 'Solubility of indium hydroxide in solution of sodium hydroxide', Russian Journal of Inorganic Chemistry, vol. 5, pp. 1996–8, in WC Sheets, E Mugnier, A Barnabé, TJ Marks & KR Poeppelmeier 2006, 'Hydrothermal synthesis of delafossite-type oxides', Chemistry of Materials, vol. 18, pp. 7–20 (15), doi:10.1021/cm051791c
- Jensen WB 2003, 'The place of zinc, cadmium and mercury in the periodic table,' Journal of Chemical Education, vol. 80, no. 8, pp. 952‒61, doi:10.1021/ed080p952
- Jensen WB 2008, 'Is mercury now a transition element?', Journal of Chemical Education, vol. 85, no. 9, pp. 1182‒1183, doi:10.1021/ed085p1182
- Jezequel G & Thomas J 1997, 'Experimental band structure of semimetal bismuth', Physical Review B, vol. 56, no. 11, pp. 6620–6, doi:10.1103/PhysRevB.56.6620
- Johansen G & Mackintosh AR 1970, 'Electronic structure and phase transitions in ytterbium', Solid State Communications, vol. 8, no. 2, pp. 121–4
- Joshua SJ 1991, Symmetry principles and magnetic symmetry in solid state physics, Andrew Hilger, Bristol, ISBN 0750300701
- Kauzlarich SM 2005, 'Zintl compounds' in RB King (ed.), Encyclopedia of inorganic chemistry, vol. 8, John Wiley & Sons, Chichester, pp. 6006–14, ISBN 9780470860786
- Kauzlarich SM, Payne AC & Webb DJ 2002, 'Magnetism and magnetotransport properties of transition metal zintl isotypes', in JS Miller & M Drillon (eds), Magnetism: Molecules to Materials III, Wiley-VCH, Weinheim, pp. 37–62, ISBN 3527303022
- Kent A 1993, Experimental low temperature physics, American Institute of Physics, New York, ISBN 1563960303
- King RB 1995, Chemistry of the main group elements, VCH Publishers, New York, ISBN 1560816791
- King RB 2004, 'The metallurgist’s periodic table and the Zintl-Klemm concept', in DH Rouvray DH & RB King (eds), The periodic table: into the 21st century, Institute of Physics Publishing, Philadelphia, ISBN, 9780863802928, pp. 189–206.
- King RB & Schleyer R 2004, 'Theory and concepts in main-group cluster chemistry', in M Driess and H Nöth (eds), Molecular clusters of the main group elements, Wiley-VCH, Chichester, pp. 1–33, ISBN 9783527614370
- Klemm W 1950, 'Einige probleme aus der physik und der chemie der halbmetalle und der metametalle', Angewandte Chemie, vol. 62, no. 6, pp. 133–42
- Kneip R 1996, 'Eduard Zintl: His life and scholarly work' in SM Kauzlarich (ed.), Chemistry, structure and bonding of zintl phases and ions, VCH, New York, pp. xvi–xxx, ISBN 1560819006
- Legut D, Friák M & Šob M 2010, 'Phase stability, elasticity, and theoretical strength of polonium from first principles,' Physical Review B, vol. 81, pp. 214118–1 to 19, doi:10.1103/PhysRevB.81.214118
- Leman JT & Barron AR 2005, 'Indium: Inorganic chemistry', Encyclopedia of Inorganic Chemistry, RB King (ed.), 2nd ed., Wiley, pp. 1526–1531
- Liang SC, King RA & White CET 1968, 'Indium', in CA Hampel (ed.), The encyclopedia of the chemical elements, Reinhold, New York, pp. 283–290
- Lidin RA 1996, Inorganic substances handbook, begell house, New York, ISBN 1567000657
- Liptrot FJ 2001, 'Overhead lines', in HM Ryan (ed.), High voltage electrical engineering and testing, 2nd ed., The Institute of Electrical Engineers, London, pp. 167‒211, ISBN 0852967756
- Lister, T 1998, Industrial chemistry case studies: Industrial processes in the 1990s, The Royal Society of Chemistry, London, ISBN 0854049258
- Liu H, Knowles CR & Chang LLY 1995, 'Extent of solid solution in Pb-Sn and Sb-Bi chalcogenides', The Canadian Mineralogist, vol.33, pp. 115–128
- Lyons A 2007, Materials for architects & builders, 3rd ed., Elsevier, Oxford, ISBN 9780750669405
- Mackay KM & Mackay RA 1989, Introduction to modern inorganic chemistry, 4th ed., Blackie, Glasgow, ISBN 0748764208
- Massalski TB (ed.) 1986, Noble metal alloys: phase diagrams, alloy phase stability, thermodynamic aspects, properties and special features, proceedings of the TMS Alloy Phase Committee, the TMS Thermodynamics Committee, and the American Society for Metals Alloy Phase Diagram Data Committee, held at the Metallurgical Society of AIME Annual Meeting, February 24‒28, 1985, The Society, Warrendale, Portland, ISBN 9780873390118
- Massey AG 2000, Main group chemistry, 2nd ed, John Wiley & Sons, Chichester, ISBN 0471490377
- McQuarrie DA, Rock PA & Gallogly EB 2010, 'Interchapter 1: The main group metals', General chemistry, 4th ed., University Science Books, Mill Valley, California, ISBN 9781891389603
- Messler RW 2011, Integral mechanical attachment: A resurgence of the oldest method of joining, Elsevier, Burlington, Massachusetts, ISBN 9780750679657
- Miller GJ, Lee C & Choe W 2002, 'Structure and bonding around the Zintl border', in G Meyer, D Naumann & L Wesermann (eds), Inorganic chemistry highlights, Wiley-VCH, Weinheim, pp. 21–53, ISBN 3527302654
- Mittemeijer EJ 2010, Fundamentals of materials science: The microstructure–property relationship using metals as model systems, Springer-Verlag, Berlin, ISBN 9783642104992
- Moeller T 1952, Inorganic chemistry: An advanced textbook, John Wiley & Sons, New York
- Müller M 1992, Inorganic structural chemistry, 2nd ed., John Wiley & Sons, Chichester, ISBN 0471937177
- Murray J 1809, A system of chemistry, 2nd ed., vol. 3, Longman, Hurst, Rees and Orme; and John Murray, London
- Noble IG 1985, 'Structural fire protection of cargo ships and guidance on the requirements of the Merchant Shipping (Fire Protection) Regulations 1984', discussion, in Ship fires in the 1980s, Tuesday 3 and Wednesday 4 December 1985 at the Institute of Marine Engineers, pp. 20–22, Marine Management (Holdings), London, c1986, ISBN 0907206158
- Norman NC 1997, Periodicity and the s- and p-block elements, Oxford University, Oxford, ISBN 0198559615
- Ogata S, Li J & Yip S 2002, 'Ideal pure shear strength of aluminium and copper', Science, vol. 298, no. 5594, 25 October, pp. 807–10, doi:10.1126/science.1076652
- Oxford English Dictionary 1989, 2nd ed., Oxford University, Oxford, ISBN 0198612133
- Parish RV 1977, The metallic elements, Longman, London, ISBN 0582442788
- Pashaey BP & Seleznev VV 1973, 'Magnetic susceptibility of gallium-indium alloys in liquid state', Russian Physics Journal, vol. 16, no. 4, pp. 565–6, doi:10.1007/BF00890855
- Patnaik, P 2003, Handbook of inorganic chemicals, McGraw-Hill, New York, ISBN 9780070494398
- Pauling L 1988, General chemistry, Dover Publications, New York, ISBN 0486656225
- Petrii OA 2012, 'Chemistry, electrochemistry and electrochemical applications', in J Garche, C Dyer, P Moseley, Z Ogumi, D Rand & B Scrosati (eds), Encyclopedia of electrochemica power sources, Elsevier B.V., Amsterdam, ISBN 9780444520937
- Phillips CSG & Williams RJP 1965, Inorganic chemistry, II: Metals, Clarendon Press, Oxford
- Polmear I 2006, Light alloys: From traditional alloys to nanocrystals, 4th ed., Elsevier, Oxford, ISBN 0750663715
- Poole CP 2004, Encyclopedic dictionary of condensed matter physics, vol. 1 A–M, trans. from Translated from the original Russian ed., published National Academy of Sciences of Ukraine, 1996–1998, Elsevier, Amsterdam, ISBN 0120883988
- Ramroth WT 2006, Thermo-mechanical structural modelling of FRP composite sandwich panels exposed to fire, PhD thesis, University of California, San Diego, ISBN 9780542856174
- Rankin WJ 2011, Minerals, metals and sustainability: Meeting future material needs, CSIRO Publishing, Collingwood, ISBN 9780643097261
- Rayner-Canham G & Overton T 2006, Descriptive inorganic chemistry, 4th ed., WH Freeman, New York, ISBN 0716789639
- Reid D, Groves G, Price C & Tennant I 2011, Science for the New Zealand curriculum Year 11, Cambridge University, Cambridge, ISBN 9780521186186
- Roget's 21st Century Thesaurus, 3rd ed, Philip Lief Group
- Roher GS 2001, Structure and bonding in crystalline materials, Cambridge University Press, Cambridge, ISBN 0521663792
- Ropp RC 2012, Encyclopedia of the alkaline earth compounds, Elsevier, Oxford, ISBN 9780444595508
- Roscoe HE & Schorlemmer FRS 1894, A treatise on chemistry: Volume II: The metals, D Appleton, New York
- Russell AM & Lee KL 2005, Structure-property relations in nonferrous metals, Wiley-Interscience, New York, ISBN 047164952X
- Samsonov GV 1968, Handbook of the physiochemical properties of the elements, I F I/Plenum, New York
- Sargent-Welch VWR International 2008, Chart of the elements: With electron distribution, Buffalo Grove, Illinois
- Savitsky EM 1961, The influence of temperature on the mechanical properties of metals and alloys, Stanford University Press, Stanford
- Sazhin NP 1961, 'Development of the metallurgy of the rare and minor metals in the USSR,' in IP Bardin (ed.), Metallurgy of the USSR, 1917-1957, volume 1, originally published by Metallurgizdat, State Scientific and Technical Publishing House of Literature on Ferrous and Nonferrous Metallurgy, Moscow, 1958; published for the National Science Foundation, Washington, DC and the Department of the Interior, USA by the Israel Program for Scientific Translations, Jerusalem, p.p. 744–64
- Schwartz M 2010, Encyclopedia and handbook of materials, parts and finishes, 2nd ed., CRC Press, Boca Raton, Florida, ISBN 1566766613
- Schweitzer PA 2003, Metallic materials: Physical, mechanical, and corrosion properties, Marcel Dekker, New York, ISBN 0824708784
- Schwietzer GK & Pesterfield LL 2010, The aqueous chemistry of the elements, Oxford University, Oxford, ISBN 019539335X
- Scott EC & Kanda FA 1962, The nature of atoms and molecules: A general chemistry, Harper & Row, New York
- Sequeira CAC 2013, 'Diffusion coatings for the oil industry', in R Javaherdashti, C Nwaoha, H Tan (eds), Corrosion and materials in the oil and gas industries, RC Press, Boca Raton
- Sevov SC, Ostenson JE & Corbett JD 1993, 'K8In10Hg: a Zintl phase with isolated In10Hg clusters', Journal of Alloys and Compounds, vol. 202, nos. 1‒2, pp. 289–294, doi:10.1016/0925-8388(93)90551-W
- Sidgwick NV 1937, The electronic theory of valence, Oxford University Press, London
- Slater JC 1939, Introduction to chemical physics, McGraw-Hill Book Company, New York
- Smith DW 1990, Inorganic substances: A prelude to the study of descriptive inorganic chemistry, Cambridge University, Cambridge, ISBN 0521337380
- Solov'eva VD, Svirchevskaya EG, Bobrova VV & El'tsov NM 1973, 'Solubility of copper, cadmium, and indium oxides in sodium hydroxide solutions', Trudy Instittua Metallurgii i Obogashcheniya, Akademiya Nauk Kazakhskoi SSR (Transactions of the Institute of Metallurgy and Ore Dressing, Academy of Sciences of the Kazakh SSR) vol. 49, pp. 37–44
- Sorensen EMB 1991, Metal poisoning in fish, CRC Press, Boca Raton, Florida, ISBN 0849342686
- Steele D 1966, The chemistry of the metallic elements, Pergamon Press, Oxford
- Strathern P 2000, Mendeleyev's dream: The quest for the elements, Hamish Hamilton, London, ISBN 024114065X
- Taylor MJ & Brothers PJ 1993, 'Inorganic derivatives of the elements', in AJ Downs (ed.), Chemistry of aluminium, gallium, indium and thallium, Chapman & Hall, London, ISBN 075140103X
- Taylor N, Derbogosian M, Ng W, Stubbs A, Stokes R, Bowen S, Raphael S & Moloney J 2007, Study on chemistry 1, John Wiley & Sons, Milton, Queensland, ISBN 9780731404186
- Tóth I & Győri B 2005, 'Thallium: Inorganic chemistry', Encyclopedia of Inorganic Chemistry, RB King (ed.), 2nd ed., John Wiley & Sons, New York, ISBN 0471936200 (set)
- US Department of Transportation, Maritime Administration 1987, Marine fire prevention, firefighting and fire safety, Washington DC
- Van Wert LR 1936, An introduction to physical metallurgy, McGraw-Hill Book Company, New York
- Vargel C 2004, Corrosion of aluminium, Elsevier, Amsterdam, ISBN 0080444954
- Walker JD, Enache M & Newman MC 2013, Fundamental QSARS for metal ions, CRC Press, Boca Raton, Florida, ISBN 9781420084337
- Wanamaker E & Pennington HR 1921, Electric arc welding, Simmons-Boardman, New York
- Wells AF 1985, Structural inorganic chemistry, 5th ed., Clarendon, Oxford, ISBN 0198553706
- Whitten KW, Davis RE, Peck LM & Stanley GG 2007, Chemistry, 8th ed., Thomson Brooks/Cole, Belmont, California, ISBN 0495014494
- Wiberg N 2001, Inorganic chemistry, Academic Press, San Diego, ISBN 0123526515
- Xia S & Bobev S 2006, 'Ba11Cd8Bi14: Bismuth zigzag chains in a ternary alkaline-earth transition-metal Zintl phase', Inorganic Chemistry, vol. 45, no. 18, pp. 7126–7132, doi:10.1021/ic060583z
- Young JA, Malik JG, Quagliano JV & Danehy JP 1969, 'Chemical queries. Especially for introductory chemistry teachers: Do elements in the zinc subgroup belong to the transition series?', Journal of Chemical Education, vol. 46, no. 4, pp. 227‒229 (228), doi:10.1021/ed046p227
- Zubieta JA & Zuckerman JJ 2009, 'Structural tin chemistry', in SJ Lippard (ed.), Progress in inorganic chemistry, vol. 24, pp. 251–476 (260), ISBN 9780470166758
|Periodic table (Large version)|