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  2. Elemental analysis - Wikipedia

    en.wikipedia.org/wiki/Elemental_analysis

    Elemental analysis is a process where a sample of some material (e.g., soil, waste or drinking water, bodily fluids, minerals, chemical compounds) is analyzed for its elemental and sometimes isotopic composition. [citation needed] Elemental analysis can be qualitative (determining what elements are present), and it can be quantitative ...

  3. Abundance of elements in Earth's crust - Wikipedia

    en.wikipedia.org/wiki/Abundance_of_elements_in...

    The Earth's crust is one "reservoir" for measurements of abundance. A reservoir is any large body to be studied as unit, like the ocean, atmosphere, mantle or crust. Different reservoirs may have different relative amounts of each element due to different chemical or mechanical processes involved in the creation of the reservoir. [1]: 18.

  4. Curie (unit) - Wikipedia

    en.wikipedia.org/wiki/Curie_(unit)

    The curie (symbol Ci) is a non- SI unit of radioactivity originally defined in 1910. According to a notice in Nature at the time, it was to be named in honour of Pierre Curie, [1] but was considered at least by some to be in honour of Marie Curie as well, [2] and is in later literature considered to be named for both.

  5. Atomic units - Wikipedia

    en.wikipedia.org/wiki/Atomic_units

    Atomic units. The atomic units are a system of natural units of measurement that is especially convenient for calculations in atomic physics and related scientific fields, such as computational chemistry and atomic spectroscopy. They were originally suggested and named by the physicist Douglas Hartree. [1]

  6. List of scientists whose names are used as units - Wikipedia

    en.wikipedia.org/wiki/List_of_scientists_whose...

    The International System of Units (abbreviated SI from French: Système international d'unités) is the most widely used system of units of measurement. There are 7 base units and 22 derived units [1] (excluding compound units). These units are used both in science and in commerce.

  7. Dalton (unit) - Wikipedia

    en.wikipedia.org/wiki/Dalton_(unit)

    The dalton or unified atomic mass unit (symbols: Da or u) is a unit of mass defined as ⁠ 1 12 ⁠ of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest. [1][2] It is a non-SI unit accepted for use with SI. The atomic mass constant, denoted mu, is defined identically, giving mu = ⁠ 1 12 ...

  8. List of measuring instruments - Wikipedia

    en.wikipedia.org/wiki/List_of_measuring_instruments

    Time. Watch, a time measurement device. In the past, a common time measuring instrument was the sundial. Today, the usual measuring instruments for time are clocks and watches. For highly accurate measurement of time an atomic clock is used. Stopwatches are also used to measure time in some sports.

  9. Elementar - Wikipedia

    en.wikipedia.org/wiki/Elementar

    Elementar is specialized in the development and production of elemental analyzers for the measurement of carbon, nitrogen, sulphur, hydrogen and oxygen for product quality and purity control of food, fuels, chemicals and pharmaceuticals. The production facility is located in Langenselbold, Hesse, Germany. [20]