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  2. Parts-per notation - Wikipedia

    en.wikipedia.org/wiki/Parts-per_notation

    Parts-per notation is often used describing dilute solutions in chemistry, for instance, the relative abundance of dissolved minerals or pollutants in water.The quantity "1 ppm" can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution.

  3. Pnictogen - Wikipedia

    en.wikipedia.org/wiki/Pnictogen

    The soils contain 1 part per million of antimony on average, and seawater contains 300 parts per trillion on average. A typical human has 28 parts per billion of antimony by weight. Some elemental antimony occurs in silver deposits. [14] Bismuth makes up 48 parts per billion of the earth's crust, making it the 70th most abundant element.

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

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

    Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number; [5] siderophiles shown in yellow Graphs of abundance against atomic number can reveal patterns relating abundance to stellar nucleosynthesis and geochemistry.

  5. Biomagnification - Wikipedia

    en.wikipedia.org/wiki/Biomagnification

    Biomagnification is the buildup of concentration of a substance (x) in a food chain. For example the DDT concentration in parts per million increases with trophic level. Concentrations build up in organism's fat and tissue. Predators accumulate higher levels than prey.

  6. Air pollutant concentrations - Wikipedia

    en.wikipedia.org/wiki/Air_pollutant_concentrations

    1 volume percent = 10,000 ppmv (i.e., parts per million by volume) with a million being defined as 10 6. Care must be taken with the concentrations expressed as ppbv to differentiate between the British billion which is 10 12 and the USA billion which is 10 9 (also referred to as the long scale and short scale billion, respectively).

  7. pCO2 - Wikipedia

    en.wikipedia.org/wiki/PCO2

    The pCO 2 of Earth's atmosphere has risen from approximately 280 ppm (parts-per-million) to a mean 2019 value of 409.8 ppm as a result of anthropogenic release of carbon dioxide from fossil fuel burning. [citation needed] This is the highest atmospheric concentration to have existed on Earth for at least the last 800,000 years. [1]

  8. Carbon dioxide - Wikipedia

    en.wikipedia.org/wiki/Carbon_dioxide

    It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), [a] or about 0.042% (as of May 2022) having risen from pre-industrial levels of 280 ppm or about 0.028%. [10] [11] Burning fossil fuels is the main cause of these increased CO 2 concentrations, which are the primary cause of climate change. [12]

  9. PPM - Wikipedia

    en.wikipedia.org/wiki/PPM

    Temperature coefficient, in parts per million per Kelvin (ppm/K) or per degree Celsius (ppm/C) Topics referred to by the same term This disambiguation page lists articles associated with the title PPM .