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  2. Yttrium - Wikipedia

    en.wikipedia.org/wiki/Yttrium

    3 as a starting material, obtained from Y 2 O 3 and concentrated hydrochloric acid and ammonium chloride. [26] [27] Hapticity is a term to describe the coordination of a group of contiguous atoms of a ligand bound to the central atom; it is indicated by the Greek letter eta, η.

  3. Oxygen - Wikipedia

    en.wikipedia.org/wiki/Oxygen

    At standard temperature and pressure, two oxygen atoms will bind covalently to form dioxygen, a colorless and odorless diatomic gas with the chemical formula O 2. Dioxygen gas currently constitutes 20.95% molar fraction of the Earth's atmosphere, though this has changed considerably over long periods of time in Earth's history.

  4. Yttrium compounds - Wikipedia

    en.wikipedia.org/wiki/Yttrium_compounds

    Yttrium and pnictides can form compounds with the chemical formula YE (E = N, P, As, Sb). They can be hydrolyzed in humid air and emit volatile hydrides EH 3. Yttrium and carbon can form a variety of compounds, such as Y 2 C 3, [9] YC 2. [10] They can be made in several ways: 2 Y + 3 C → Y 2 C 3 Y 2 O 3 + 7 C → 2 YC 2 + 3 CO ↑

  5. Chemical formula - Wikipedia

    en.wikipedia.org/wiki/Chemical_formula

    A molecular formula enumerates the number of atoms to reflect those in the molecule, so that the molecular formula for glucose is C 6 H 12 O 6 rather than the glucose empirical formula, which is CH 2 O. However, except for very simple substances, molecular chemical formulae lack needed structural information, and are ambiguous.

  6. Oxyanion - Wikipedia

    en.wikipedia.org/wiki/Oxyanion

    An oxyanion, or oxoanion, is an ion with the generic formula A x O z− y (where A represents a chemical element and O represents an oxygen atom). Oxyanions are formed by a large majority of the chemical elements. [1] The formulae of simple oxyanions are determined by the octet rule. The corresponding oxyacid of an oxyanion is the compound H z ...

  7. Allotropes of oxygen - Wikipedia

    en.wikipedia.org/wiki/Allotropes_of_oxygen

    Triatomic oxygen (ozone, O 3) is a very reactive allotrope of oxygen that is a pale blue gas at standard temperature and pressure. Liquid and solid O 3 have a deeper blue color than ordinary O 2, and they are unstable and explosive. [5] [6] In its gas phase, ozone is destructive to materials like rubber and fabric and is damaging to lung tissue ...

  8. List of chemical elements - Wikipedia

    en.wikipedia.org/wiki/List_of_chemical_elements

    A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...

  9. Chemical element - Wikipedia

    en.wikipedia.org/wiki/Chemical_element

    A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8, meaning each oxygen atom has 8 protons in its nucleus.