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  2. Native metal - Wikipedia

    en.wikipedia.org/wiki/Native_metal

    Metals are not the only type of chemical element that can occur in the native state. Non-metallic elements occurring in the native state include carbon, sulfur, and selenium. Silicon, a semi-metal, has rarely been found in the native state as small inclusions in gold.

  3. Properties of metals, metalloids and nonmetals - Wikipedia

    en.wikipedia.org/wiki/Properties_of_metals...

    Metals comprise the large majority of the elements, and can be subdivided into several different categories. From left to right in the periodic table, these categories include the highly reactive alkali metals ; the less-reactive alkaline earth metals , lanthanides , and radioactive actinides ; the archetypal transition metals ; and the ...

  4. Uranium - Wikipedia

    en.wikipedia.org/wiki/Uranium

    Uranium is a chemical element; it has symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium radioactively decays, usually by emitting an alpha particle.

  5. Periodic table - Wikipedia

    en.wikipedia.org/wiki/Periodic_table

    The periodic table is a graphic description of the periodic law, which states that the properties and atomic structures of the chemical elements are a periodic function of their atomic number. Elements are placed in the periodic table according to their electron configurations , [41] the periodic recurrences of which explain the trends in ...

  6. Copper - Wikipedia

    en.wikipedia.org/wiki/Copper

    Copper. face-centered cubic (fcc) ( cF4) Copper is a chemical element; it has symbol Cu (from Latin cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and ...

  7. Iridium - Wikipedia

    en.wikipedia.org/wiki/Iridium

    Iridium is a chemical element; it has symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, it is considered the second-densest naturally occurring metal (after osmium) with a density of 22.56 g/cm 3 (0.815 lb/cu in) [8] as defined by experimental X-ray crystallography. [a] 191 Ir and 193 Ir ...

  8. Metal - Wikipedia

    en.wikipedia.org/wiki/Metal

    A metal (from Ancient Greek μέταλλον (métallon) 'mine, quarry, metal') is a material that, when polished or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. These properties are all associated with having electrons available at the Fermi level, as against nonmetallic materials which do not. [1] : .

  9. Biological roles of the elements - Wikipedia

    en.wikipedia.org/wiki/Biological_roles_of_the...

    The remaining elements found in living things are primarily metals that play a role in determining protein structure. Examples include iron, essential to hemoglobin; and magnesium, essential to chlorophyll. Some elements are essential only to certain taxonomic groups of organisms, particularly the prokaryotes.