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Chemical symbol. The periodic table, elements being denoted by their symbols. Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols, normally consist of one or two letters ...
Chemical nomenclature. Chemical nomenclature is a set of rules to generate systematic names for chemical compounds. The nomenclature used most frequently worldwide is the one created and developed by the International Union of Pure and Applied Chemistry (IUPAC). IUPAC Nomenclature ensures that each compound (and its various isomers) have only ...
Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is 23 Na. The free metal does not occur in nature and must be prepared from compounds. Sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and halite (NaCl).
Battery numbering. IEC 60086 battery type designation system. Examples of the IEC nomenclature are batteries coded R20, 4R25X, 4LR25-2, 6F22, 6P222/162, CR17345 and LR2616J. The letters and numbers in the code indicate the number of cells, cell chemistry, shape, dimensions, the number of parallel paths in the assembled battery and any modifying ...
The study of the absorption or release of heat during a chemical reaction. thermodynamic stability. The condition of a system being in its lowest energy state with its environment (equilibrium). thermodynamics. The study of the effects of changing temperature, volume or pressure (or work, heat, and energy) on a macroscopic scale.
A chemical element is a chemical substance that cannot be broken down into other substances by chemical reactions. The basic particle that constitutes a chemical element is the atom. Elements are identified by the number of protons in their nucleus, [ 1] known as the element's atomic number. [ 2] For example, oxygen has an atomic number of 8 ...
National Security Department (noted as NS), a law enforcement agency in Hong Kong. National service, a name for the conscription system of some militaries. National Socialism or Nazism, the ideology held by, among other political parties, the National Socialist German Workers Party. New Serbia (political party) ( Nova Srbija ), a political ...
A nanosecond (ns) is a unit of time in the International System of Units (SI) equal to one billionth of a second, that is, 1⁄1 000 000 000 of a second, or 10 −9 seconds. The term combines the SI prefix nano- indicating a 1 billionth submultiple of an SI unit (e.g. nanogram, nanometre, etc.) and second, the primary unit of time in the SI.