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  2. Group 7 element - Wikipedia

    en.wikipedia.org/wiki/Group_7_element

    All group 7 elements crystallize in the hexagonal close packed (hcp) structure except manganese, which crystallizes in the body centered cubic (bcc) structure. Bohrium is also expected to crystallize in the hcp structure. [1] The table below is a summary of the key physical properties of the group 7 elements. The question-marked value is ...

  3. Reactivity (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Reactivity_(chemistry)

    In pure compounds, reactivity is regulated by the physical properties of the sample. For instance, grinding a sample to a higher specific surface area increases its reactivity. In impure compounds, the reactivity is also affected by the inclusion of contaminants. In crystalline compounds, the crystalline form can also affect reactivity. However ...

  4. List of chemistry mnemonics - Wikipedia

    en.wikipedia.org/wiki/List_of_chemistry_mnemonics

    2.5.7 Group 17 (Halogens) 2.5.8 Group 18 (noble gases) 3 Properties of elements. Toggle Properties of elements subsection. ... Toggle Reactions and ions subsection.

  5. Bohrium - Wikipedia

    en.wikipedia.org/wiki/Bohrium

    The lighter group 7 elements are known to form volatile heptoxides M 2 O 7 (M = Mn, Tc, Re), so bohrium should also form the volatile oxide Bh 2 O 7. The oxide should dissolve in water to form perbohric acid, HBhO 4. Rhenium and technetium form a range of oxyhalides from the halogenation of the oxide.

  6. Block (periodic table) - Wikipedia

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

    The p-block elements show variable oxidation states usually differing by multiples of two. The reactivity of elements in a group generally decreases downwards. (Helium breaks this trend in group 18 by being more reactive than neon, but since helium is actually an s-block element, the p-block portion of the trend remains intact.)

  7. Reactivity series - Wikipedia

    en.wikipedia.org/wiki/Reactivity_series

    The reactivity series is sometimes quoted in the strict reverse order of standard electrode potentials, when it is also known as the "electrochemical series". [8] The following list includes the metallic elements of the first six periods. It is mostly based on tables provided by NIST.

  8. Periodic trends - Wikipedia

    en.wikipedia.org/wiki/Periodic_trends

    The periodic trends in properties of elements. In chemistry, periodic trends are specific patterns present in the periodic table that illustrate different aspects of certain elements when grouped by period and/or group. They were discovered by the Russian chemist Dmitri Mendeleev in 1863.

  9. Rhenium - Wikipedia

    en.wikipedia.org/wiki/Rhenium

    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 any element.