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  2. Oxygen - Wikipedia

    en.wikipedia.org/wiki/Oxygen

    Molar heat capacity (O 2) 29.378 J/(mol·K) ... Most of the mass of living organisms is oxygen as a component of water, the major constituent of lifeforms.

  3. Molar mass - Wikipedia

    en.wikipedia.org/wiki/Molar_mass

    The molar mass of atoms of an element is given by the relative atomic mass of the element multiplied by the molar mass constant, M u ≈ 1.000 000 × 10 −3 kg/mol ≈ 1 g/mol. For normal samples from Earth with typical isotope composition, the atomic weight can be approximated by the standard atomic weight [ 2 ] or the conventional atomic weight.

  4. Isotopes of oxygen - Wikipedia

    en.wikipedia.org/wiki/Isotopes_of_oxygen

    Oxygen-15 is a radioisotope, often used in positron emission tomography (PET). It can be used in, among other things, water for PET myocardial perfusion imaging and for brain imaging. [20] [21] It has an atomic mass of 15.003 0656 (5), and a half-life of 122.266(43) s. It is produced through deuteron bombardment of nitrogen-14 using a cyclotron ...

  5. Molecular mass - Wikipedia

    en.wikipedia.org/wiki/Molecular_mass

    The molecular mass and relative molecular mass are distinct from but related to the molar mass. The molar mass is defined as the mass of a given substance divided by the amount of the substance, and is expressed in grams per mol (g/mol). That makes the molar mass an average of many particles or molecules (potentially containing different ...

  6. Gas composition - Wikipedia

    en.wikipedia.org/wiki/Gas_composition

    ISO TR 29922-2017 provides a definition for standard dry air which specifies an air molar mass of 28,965 46 ± 0,000 17 kg·kmol-1. [2] GPA 2145:2009 is published by the Gas Processors Association. It provides a molar mass for air of 28.9625 g/mol, and provides a composition for standard dry air as a footnote. [3]

  7. Atomic mass - Wikipedia

    en.wikipedia.org/wiki/Atomic_mass

    Thus, molecular mass and molar mass differ slightly in numerical value and represent different concepts. Molecular mass is the mass of a molecule, which is the sum of its constituent atomic masses. Molar mass is an average of the masses of the constituent molecules in a chemically pure but isotopically heterogeneous ensemble.

  8. Mercury(II) oxide - Wikipedia

    en.wikipedia.org/wiki/Mercury(II)_oxide

    Molar mass: 216.591 g·mol −1 Appearance Yellow or red solid Odor: odorless ... Joseph Priestley discovered that oxygen was released by heating mercuric oxide, ...

  9. Potassium oxide - Wikipedia

    en.wikipedia.org/wiki/Potassium_oxide

    Potassium oxide (K 2 O) is an ionic compound of potassium and oxygen. It is a base. This pale yellow solid is the simplest oxide of potassium. It is a highly reactive compound that is rarely encountered. Some industrial materials, such as fertilizers and cements, are assayed assuming the percent composition that would be equivalent to K 2 O.