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  2. Rhenium - Wikipedia

    en.wikipedia.org/wiki/Rhenium

    Rhenium is a chemical element; it has symbol Re and atomic number 75. It is a silvery-gray, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the Earth's crust. It has one of the highest melting and boiling points of ...

  3. Rhenium compounds - Wikipedia

    en.wikipedia.org/wiki/Rhenium_compounds

    Rhenium compounds are compounds formed by the transition metal rhenium (Re). Rhenium can form in many oxidation states , and compounds are known for every oxidation state from -3 to +7 except -2, although the oxidation states +7, +4, and +3 are the most common. [ 1 ]

  4. Group 7 element - Wikipedia

    en.wikipedia.org/wiki/Group_7_element

    It is the raw material for all rhenium compounds, being the volatile fraction obtained upon roasting the host ore. [26] Rhenium, in addition to the +4 and +7 oxidation states, also forms a trioxide. It can be formed by reducing rhenium(VII) oxide with carbon monoxide at 200 C or elemental rhenium at 4000 C. [27] It can also be reduced with ...

  5. Quadruple bond - Wikipedia

    en.wikipedia.org/wiki/Quadruple_bond

    Many other compounds with quadruple bonds between transition metal atoms have been described, often by Cotton and his coworkers. Isoelectronic with the dirhenium compound is the salt K 4 [Mo 2 Cl 8] (potassium octachlorodimolybdate). [7] An example of a ditungsten compound with a quadruple bond is ditungsten tetra(hpp).

  6. Transition metal - Wikipedia

    en.wikipedia.org/wiki/Transition_metal

    The period 6 and 7 transition metals also add core (n − 2)f 14 electrons, which are omitted from the tables below. The p orbitals are almost never filled in free atoms (the one exception being lawrencium due to relativistic effects that become important at such high Z), but they can contribute to the chemical bonding in transition metal ...

  7. Pnictogen - Wikipedia

    en.wikipedia.org/wiki/Pnictogen

    The pnictogens exemplify the transition from nonmetal to metal going down the periodic table: a gaseous diatomic nonmetal (N), two elements displaying many allotropes of varying conductivities and structures (P and As), and then at least two elements that only form metallic structures in bulk (Sb and Bi; probably Mc as well).

  8. Group 8 element - Wikipedia

    en.wikipedia.org/wiki/Group_8_element

    The hardness of osmium is moderately high at 4 GPa. Because of its hardness, brittleness, low vapor pressure (the lowest of the platinum-group metals), and very high melting point (the fourth highest of all elements, after carbon, tungsten, and rhenium), solid osmium is difficult to machine, form, or work.

  9. Bohrium - Wikipedia

    en.wikipedia.org/wiki/Bohrium

    Rhenium and technetium form a range of oxyhalides from the halogenation of the oxide. The chlorination of the oxide forms the oxychlorides MO 3 Cl, so BhO 3 Cl should be formed in this reaction. Fluorination results in MO 3 F and MO 2 F 3 for the heavier elements in addition to the rhenium compounds ReOF 5 and ReF 7.