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Chemical Elements Data References
The List of data references for chemical elements is divided into datasheets that give values for many properties of the elements, together with various references. Each datasheet is sequenced by atomic number. References for chemical elements * List of chemical elements — with basic properties like standard atomic weight, m.p., b.p., abundance * Abundance of the chemical elements * Abundances of the elements (data page) — Earth's crust, sea water, Sun and solar system * Abundance of elements in Earth's crust * Atomic radii of the elements (data page) — atomic radius (empirical), atomic radius (calculated), van der Waals radius, covalent radius * Boiling points of the elements (data page) — Boiling point * Critical points of the elements (data page) — Critical point * Densities of the elements (data page) — Density (solid, liquid, gas) * Elastic properties of the elements (data page) — Young's modulus, Poisson ratio, bulk modulus, sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Datasheet
A datasheet, data sheet, or spec sheet is a document that summarizes the performance and other characteristics of a product, machine, component (e.g., an electronic component), material, subsystem (e.g., a power supply), or software in sufficient detail that allows a buyer to understand what the product is and a design engineer to understand the role of the component in the overall system. Typically, a datasheet is created by the manufacturer and begins with an introductory page describing the rest of the document, followed by listings of specific characteristics, with further information on the connectivity of the devices. In cases where there is relevant source code to include, it is usually attached near the end of the document or separated into another file. Datasheets are created, stored, and distributed via product information management or product data management systems. Depending on the specific purpose, a datasheet may offer an average value, a typical value, a ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Affinity (data Page)
This page deals with the electron affinity as a property of isolated atoms or molecules (i.e. in the gas phase). Solid state electron affinities are not listed here. Elements Electron affinity can be defined in two equivalent ways. First, as the energy that is released by adding an electron to an isolated gaseous atom. The second (reverse) definition is that electron affinity is the energy required to remove an electron from a singly charged gaseous negative ion. The latter can be regarded as the ionization energy of the –1 ion or the ''zeroth'' ionization energy. Either convention can be used. Negative electron affinities can be used in those cases where electron capture requires energy, i.e. when capture can occur only if the impinging electron has a kinetic energy large enough to excite a resonance of the atom-plus-electron system. Conversely electron removal from the anion formed in this way releases energy, which is carried out by the freed electron as kinetic energy. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionization Energies Of The Elements (data Page)
Numerical values For each atom, the column marked 1 is the first ionization energy to ionize the neutral atom, the column marked 2 is the second ionization energy to remove a second electron from the +1 ion, the column marked 3 is the third ionization energy to remove a third electron from the +2 ion, and so on. "use" and "WEL" give ionization energy in the unit kJ/mol; "CRC" gives atomic ionization energy in the unit eV. Notes * Values from CRC are ionization energies given in the unit eV; other values are molar ionization energies given in the unit kJ/mol The joule per mole (symbol: J·mol−1 or J/mol) is the unit of energy per amount of substance in the International System of Units (SI), such that energy is measured in joules, and the amount of substance is measured in moles. It is also an SI .... The first of these quantities is used in atomic physics, the second in chemistry, but both refer to the same basic property of the element. To convert from "value of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Of Vaporization
The enthalpy of vaporization (symbol ), also known as the (latent) heat of vaporization or heat of evaporation, is the amount of energy ( enthalpy) that must be added to a liquid substance to transform a quantity of that substance into a gas. The enthalpy of vaporization is a function of the pressure at which that transformation takes place. The enthalpy of vaporization is often quoted for the normal boiling temperature of the substance. Although tabulated values are usually corrected to 298 K, that correction is often smaller than the uncertainty in the measured value. The heat of vaporization is temperature-dependent, though a constant heat of vaporization can be assumed for small temperature ranges and for reduced temperature T_r \ll 1. The heat of vaporization diminishes with increasing temperature and it vanishes completely at a certain point called the critical temperature (T_r = 1). Above the critical temperature, the liquid and vapor phases are indistinguishab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heats Of Vaporization Of The Elements (data Page)
Heat of vaporization Notes * Values refer to the enthalpy Enthalpy , a property of a thermodynamic system, is the sum of the system's internal energy and the product of its pressure and volume. It is a state function used in many measurements in chemical, biological, and physical systems at a constant ... change in the conversion of liquid to gas at the boiling point (normal, 101.325 kPa). References Zhang et al. CRC As quoted from various sources in an online version of: * David R. Lide (ed.), ''CRC Handbook of Chemistry and Physics, 84th Edition''. CRC Press. Boca Raton, Florida, 2003; Section 6, Fluid Properties; Enthalpy of Vaporization GME *Kugler HK & Keller C (eds) 1985, ''Gmelin handbook of inorganic and organometallic chemistry,'' 8th ed., 'At, Astatine', system no. 8a, Springer-Verlag, Berlin, , pp. 116–117 LNG As quoted from various sources in: * J.A. Dean (ed.), ''Lange's Handbook of Chemistry'' (15th Edition), McGraw-Hill, 1999; Section 6, Therm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Of Fusion
In thermodynamics, the enthalpy of fusion of a substance, also known as (latent) heat of fusion, is the change in its enthalpy resulting from providing energy, typically heat, to a specific quantity of the substance to change its state from a solid to a liquid, at constant pressure. It is the amount of energy required to convert one mole of solid into liquid For example, when melting 1 kg of ice (at 0 °C under a wide range of pressures), 333.55 kJ of energy is absorbed with no temperature change. The heat of solidification (when a substance changes from liquid to solid) is equal and opposite. This energy includes the contribution required to make room for any associated change in volume by displacing its environment against ambient pressure. The temperature at which the phase transition occurs is the melting point or the freezing point, according to context. By convention, the pressure is assumed to be unless otherwise specified. Overview The 'enthalpy' of fusion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heats Of Fusion Of The Elements (data Page)
Heat of fusion Notes * Values refer to the enthalpy change between the liquid phase and the most stable solid phase at the melting point (normal, 101.325 kPa). References CRC As quoted from various sources in an online version of: * David R. Lide (ed), ''CRC Handbook of Chemistry and Physics, 84th Edition''. CRC Press. Boca Raton, Florida, 2003; Section 6, Fluid Properties; Enthalpy of Fusion LNG As quoted from various sources in: * J.A. Dean (ed), ''Lange's Handbook of Chemistry'' (15th Edition), McGraw-Hill, 1999; Section 6, Thermodynamic Properties; Table 6.4, Heats of Fusion, Vaporization, and Sublimation and Specific Heat at Various Temperatures of the Elements and Inorganic Compounds WEL As quoted at http://www.webelements.com/ from these sources: * G.W.C. Kaye and T.H. Laby in ''Tables of physical and chemical constants'', Longman, London, UK, 15th edition, 1993. * D.R. Lide, (ed.) in ''Chemical Rubber Company handbook of chemistry and physics'', CRC Press, B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Capacity
Heat capacity or thermal capacity is a physical property of matter, defined as the amount of heat to be supplied to an object to produce a unit change in its temperature. The SI unit of heat capacity is joule per kelvin (J/K). Heat capacity is an extensive property. The corresponding intensive property is the specific heat capacity, found by dividing the heat capacity of an object by its mass. Dividing the heat capacity by the amount of substance in moles yields its molar heat capacity. The volumetric heat capacity measures the heat capacity per volume. In architecture and civil engineering, the heat capacity of a building is often referred to as its thermal mass. Definition Basic definition The heat capacity of an object, denoted by C, is the limit : C = \lim_\frac, where \Delta Q is the amount of heat that must be added to the object (of mass ''M'') in order to raise its temperature by \Delta T. The value of this parameter usually varies considerably dependin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Capacities Of The Elements (data Page)
Specific heat capacity Notes * All values refer to 25 °C and to the thermodynamically stable standard state at that temperature unless noted. * Values from CRC refer to "100 kPa (1 bar or 0.987 standard atmospheres)". Lange indirectly defines the values to be at a standard state pressure of "1 atm (101325 Pa)", although citing the same NBS and JANAF sources among others. It is assumed this inexactly refers to "ambient pressure". References CRC As quoted in an online version of: * David R. Lide (ed), ''CRC Handbook of Chemistry and Physics, 84th Edition''. CRC Press. Boca Raton, Florida, 2003; Section 4, Properties of the Elements and Inorganic Compounds; Heat Capacity of the Elements at 25 °C WEL As quoted at http://www.webelements.com/ from these sources: * R.H. Schumm, D.D. Wagman, S. Bailey, W.H. Evans, and V.B. Parker in National Bureau of Standards The National Institute of Standards and Technology (NIST) is an agency of the United States Departmen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardnesses Of The Elements (data Page)
Notes References See also *Mohs scale of mineral hardness *Mohs hardness of materials (data page) * Vickers hardness test *Brinell scale The Brinell scale characterizes the indentation hardness of materials through the scale of penetration of an indenter, loaded on a material test-piece. It is one of several definitions of hardness in materials science. History Proposed by Sw ... {{DEFAULTSORT:Hardnesses Of The Elements (Data Page) Properties of chemical elements Chemical element data pages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronegativity
Electronegativity, symbolized as , is the tendency for an atom of a given chemical element to attract shared electrons (or electron density) when forming a chemical bond. An atom's electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the associated electronegativity, the more an atom or a substituent group attracts electrons. Electronegativity serves as a simple way to quantitatively estimate the bond energy, and the sign and magnitude of a bond's chemical polarity, which characterizes a bond along the continuous scale from covalent to ionic bonding. The loosely defined term electropositivity is the opposite of electronegativity: it characterizes an element's tendency to donate valence electrons. On the most basic level, electronegativity is determined by factors like the nuclear charge (the more protons an atom has, the more "pull" it will have on electrons) and the number and lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electronegativities Of The Elements (data Page)
Electronegativity (Pauling scale) Notes * Separate values for each source are only given where one or more sources differ. * Electronegativity is not a uniquely defined property and may depend on the definition. The suggested values are all taken froWebElementsas a consistent set. * Many of the highly radioactive elements have values that must be predictions or extrapolations, but are unfortunately not marked as such. This is especially problematic for francium, which by relativistic calculations can be shown to be less electronegative than caesium, but for which the only value (0.7) in the literature predates these calculations. Electronegativity (Allen scale) References WEL As quoted at http://www.webelements.com/ from these sources: * A.L. Allred, ''J. Inorg. Nucl. Chem.'', 1961, 17, 215. * J.E. Huheey, E.A. Keiter, and R.L. Keiter in ''Inorganic Chemistry : Principles of Structure and Reactivity'', 4th edition, HarperCollins, New York, USA, 1993. CRC As quote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
