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  2. Aluminium - Wikipedia

    en.wikipedia.org/wiki/Aluminium

    Aluminium (or aluminum in North American English) is a chemical element; it has symbol Al and atomic number 13. Aluminium has a density lower than that of other common metals, about one-third that of steel. It has a great affinity towards oxygen, forming a protective layer of oxide on the surface when exposed to air.

  3. Oxidation state - Wikipedia

    en.wikipedia.org/wiki/Oxidation_state

    In Stock nomenclature, which is commonly used for inorganic compounds, the oxidation state is represented by a Roman numeral placed after the element name inside parentheses or as a superscript after the element symbol, e.g. Iron(III) oxide. The term oxidation was first used by Antoine Lavoisier to signify the reaction of a substance with oxygen.

  4. Charge number - Wikipedia

    en.wikipedia.org/wiki/Charge_number

    In that case, the charge of an ion could be written as =. The charge number in chemistry normally relates to an electric charge. This is a property of specific subatomic atoms. These elements define the electromagnetic contact between the two elements. A chemical charge can be found by using the periodic table.

  5. Effective nuclear charge - Wikipedia

    en.wikipedia.org/wiki/Effective_nuclear_charge

    In atomic physics, the effective nuclear charge of an electron in a multi-electron atom or ion is the number of elementary charges an electron experiences by the nucleus. It is denoted by Z eff . The term "effective" is used because the shielding effect of negatively charged electrons prevent higher energy electrons from experiencing the full ...

  6. Atomic number - Wikipedia

    en.wikipedia.org/wiki/Atomic_number

    The atomic number or nuclear charge number (symbol Z) of a chemical element is the charge number of its atomic nucleus. For ordinary nuclei composed of protons and neutrons , this is equal to the proton number ( n p ) or the number of protons found in the nucleus of every atom of that element.

  7. Alchemical symbol - Wikipedia

    en.wikipedia.org/wiki/Alchemical_symbol

    Alchemical symbols were used to denote chemical elements and compounds, as well as alchemical apparatus and processes, until the 18th century. Although notation was ...

  8. Formal charge - Wikipedia

    en.wikipedia.org/wiki/Formal_charge

    Formal charges in ozone and the nitrate anion. In chemistry, a formal charge (F.C. or q*), in the covalent view of chemical bonding, is the hypothetical charge assigned to an atom in a molecule, assuming that electrons in all chemical bonds are shared equally between atoms, regardless of relative electronegativity.

  9. Charge carrier density - Wikipedia

    en.wikipedia.org/wiki/Charge_carrier_density

    Charge carrier density, also known as carrier concentration, denotes the number of charge carriers per volume. In SI units, it is measured in m −3. As with any density, in principle it can depend on position. However, usually carrier concentration is given as a single number, and represents the average carrier density over the whole material.