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  2. Period 5 element - Wikipedia

    en.wikipedia.org/wiki/Period_5_element

    A period 5 element is one of the chemical elements in the fifth row (or period) of the periodic table of the chemical elements.The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the elements as their atomic number increases: a new row is begun when chemical behaviour begins to repeat, meaning that elements with similar behaviour fall ...

  3. Technetium - Wikipedia

    en.wikipedia.org/wiki/Technetium

    Period: period 5: Block ... It is a molecular metal oxide, ... A series of chemical processes yields technetium-99 metal of high purity. [81]

  4. Period (periodic table) - Wikipedia

    en.wikipedia.org/wiki/Period_(periodic_table)

    Period 5 has the same number of elements as period 4 and follows the same general structure but with one more post transition metal and one fewer nonmetal. Of the three heaviest elements with biological roles, two (molybdenum and iodine) are in this period; tungsten, in period 6, is heavier, along with several of the early lanthanides.

  5. Promethium - Wikipedia

    en.wikipedia.org/wiki/Promethium

    Promethium is one of the only two radioactive elements that are both preceded and followed in the periodic table by elements with stable forms, the other being technetium. Chemically, promethium is a lanthanide .

  6. Technetium (VII) oxide - Wikipedia

    en.wikipedia.org/wiki/Technetium(VII)_oxide

    Technetium(VII) oxide is the chemical compound with the formula Tc 2 O 7. This yellow volatile solid is a rare example of a molecular binary metal oxide, the other examples being RuO 4 , OsO 4 , and the unstable Mn 2 O 7 .

  7. Technetium compounds - Wikipedia

    en.wikipedia.org/wiki/Technetium_compounds

    It is a molecular metal oxide, analogous to manganese heptoxide. It adopts a centrosymmetric structure with two types of Tc−O bonds with 167 and 184 pm bond lengths. [3] Technetium heptoxide hydrolyzes to pertechnetate and pertechnetic acid, depending on the pH: [4] [5] Tc 2 O 7 + 2 OH − → 2 TcO 4 − + H 2 O Tc 2 O 7 + H 2 O → 2 HTcO 4 ...

  8. Group 5 element - Wikipedia

    en.wikipedia.org/wiki/Group_5_element

    Vanadium forms oxides in the +2, +3, +4 and +5 oxidation states, forming vanadium(II) oxide (VO), vanadium(III) oxide (V 2 O 3), vanadium(IV) oxide (VO 2) and vanadium(V) oxide (V 2 O 5). Vanadium(V) oxide or vanadium pentoxide is the most common, being precursor to most alloys and compounds of vanadium, and is also a widely used industrial ...

  9. Group 7 element - Wikipedia

    en.wikipedia.org/wiki/Group_7_element

    Technetium was created by bombarding molybdenum atoms with deuterons that had been accelerated by a device called a cyclotron. Technetium occurs naturally in the Earth's crust in minute concentrations of about 0.003 parts per trillion. Technetium is so rare because the half-lives of 97 Tc and 98 Tc are only 4.2 million