Isobaric specific heat of metals and metalloids under standard conditions

Isobaric specific heat of metals and metalloids under standard conditions

Junjie Chen

Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China

Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: [e-mail]

A metal is any of a class of substances characterized by high electrical and thermal conductivity as well as by malleability, ductility, and high reflectivity of light. Approximately three-quarters of all known chemical elements are metals. The most abundant varieties in the Earth's crust are aluminum, iron, calcium, sodium, potassium, and magnesium. The vast majority of metals are found in ores (mineral-bearing substances), but a few such as copper, gold, platinum, and silver frequently occur in the free state because they do not readily react with other elements. Metals are usually crystalline solids. In most cases, they have a relatively simple crystal structure distinguished by a close packing of atoms and a high degree of symmetry. Typically, the atoms of metals contain less than half the full complement of electrons in their outermost shell. Because of this characteristic, metals tend not to form compounds with each other. They do, however, combine more readily with nonmetals (for example, oxygen and sulfur), which generally have more than half the maximum number of valence electrons. Metals differ widely in their chemical reactivity. The most reactive include lithium, potassium, and radium, whereas those of low reactivity are gold, silver, palladium, and platinum. The high electrical and thermal conductivities of the simple metals (namely the non-transition metals of the periodic table) are best explained by reference to the free-electron theory. According to this concept, the individual atoms in such metals have lost their valence electrons to the entire solid, and these free electrons that give rise to conductivity move as a group throughout the solid. In the case of the more complex metals (namely the transition elements), conductivities are better explained by the band theory, which takes into account not only the presence of free electrons but also their interaction with so-called d electrons. The mechanical properties of metals, such as hardness, ability to resist repeated stressing (fatigue strength), ductility, and malleability, are often attributed to defects or imperfections in their crystal structure. The absence of a layer of atoms in its densely packed structure, for example, enables a metal to deform plastically, and prevents it from being brittle. A metalloid, in chemistry, is an imprecise term used to describe a chemical element that forms a simple substance having properties intermediate between those of a typical metal and a typical nonmetal. The term is normally applied to a group of between six and nine elements (boron, silicon, germanium, arsenic, antimony, tellurium, and possibly bismuth, polonium, astatine) found near the center of the P-block or main block of the periodic table. There is no single property which can be used to unambiguously identify an element as a metalloid. Since most metalloids tend to display semiconducting properties in at least one of their allomorphic modifications, the class might reasonably be extended to also include gray silicon (which, unlike white silicon, is a semiconductor rather than a metal) and the graphite form of carbon (which, unlike the diamond form, is a semimetal rather than an insulator). Chemically, metalloids correspond to atoms having intermediate electronegativities and an ability to display a range of both positive and negative oxidation states in their compounds.

Metals and metalloids, Isobaric specific heat (kilojoules per kelvin per kilogram)

Aluminum      0.91

Antimony      0.21

Barium      0.20

Beryllium      1.83

Bismuth      0.13

Cadmium      0.23

Calsium      0.63

Carbon Steel      0.49

Cast Iron      0.46

Cesium      0.24

Chromium      0.46

Cobalt      0.42

Copper      0.39

Gallium      0.37

Germanium      0.32

Gold      0.13

Hafnium      0.14

Indium      0.24

Iridium      0.13

Iron      0.45

Lanthanum      0.195

Lead      0.13

Lithium      3.57

Lutetium      0.15

Magnesium      1.05

Manganese      0.48

Mercury      0.14

Molybdenum      0.25

Nickel      0.44

Niobium      0.27

Osmium      0.13

Palladium      0.24

Platinum      0.13

Plutonium      0.13

Potassium      0.75

Rhenium      0.14

Rhodium      0.24

Rubidium      0.36

Ruthenium      0.24

Scandium      0.57

Selenium      0.32

Silicon      0.71

Silver      0.23

Sodium      1.21

Strontium      0.30

Tantalum      0.14

Thallium      0.13

Thorium      0.13

Tin      0.21

Titanium      0.54

Tungsten      0.13

Uranium      0.12

Vanadium      0.39

Yttrium      0.30

Zinc      0.39

Zirconium      0.27

Wrought Iron      0.50

Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: [e-mail], Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China