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  2. Period 1 element - Wikipedia

    en.wikipedia.org/wiki/Period_1_element

    A period 1 element is one of the chemical elements in the first row (or period) of the periodic table of the chemical elements.The periodic table is laid out in rows to illustrate periodic (recurring) 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 analog elements fall into the same ...

  3. Tomlin order - Wikipedia

    en.wikipedia.org/wiki/Tomlin_order

    The Tomlin order permits either party to apply to court to enforce the terms of the order, which avoids the need to start fresh proceedings. The terms of the schedule do not form part of the court order and so may remain confidential, and they may include matters outside the jurisdiction of the court or the scope of the case in hand.

  4. Limiting reagent - Wikipedia

    en.wikipedia.org/wiki/Limiting_reagent

    [1] [2] The amount of product formed is limited by this reagent, since the reaction cannot continue without it. If one or more other reagents are present in excess of the quantities required to react with the limiting reagent, they are described as excess reagents or excess reactants (sometimes abbreviated as "xs"), or to be in abundance .

  5. Period (periodic table) - Wikipedia

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

    Period 4 includes the biologically essential elements potassium and calcium, and is the first period in the d-block with the lighter transition metals. These include iron , the heaviest element forged in main-sequence stars and a principal component of the Earth, as well as other important metals such as cobalt , nickel , and copper .

  6. Chemical test - Wikipedia

    en.wikipedia.org/wiki/Chemical_test

    In chemistry, a chemical test is a qualitative or quantitative procedure designed to identify, quantify, or characterise a chemical compound or chemical group. Purposes

  7. Transition state theory - Wikipedia

    en.wikipedia.org/wiki/Transition_state_theory

    At 298 K, a reaction with ΔG ‡ = 23 kcal/mol has a rate constant of k ≈ 8.4 × 10 −5 s −1 and a half life of t 1/2 ≈ 2.3 hours, figures that are often rounded to k ~ 10 −4 s −1 and t 1/2 ~ 2 h. Thus, a free energy of activation of this magnitude corresponds to a typical reaction that proceeds to completion overnight at room ...

  8. Rate-determining step - Wikipedia

    en.wikipedia.org/wiki/Rate-determining_step

    That is, r −1 ≪ r 2, so that r 1 − r 2 ≈ 0. But the overall rate of reaction is the rate of formation of final product (here CO 2), so that r = r 2 ≈ r 1. That is, the overall rate is determined by the rate of the first step, and (almost) all molecules that react at the first step continue to the fast second step.

  9. Irving–Williams series - Wikipedia

    en.wikipedia.org/wiki/Irving–Williams_series

    The Irving–Williams series refers to the relative stabilities of complexes formed by transition metals. In 1953 Harry Irving and Robert Williams observed that the stability of complexes formed by divalent first-row transition metal ions generally increase across the period to a maximum stability at copper: Mn(II) < Fe(II) < Co(II) < Ni(II) < Cu(II) > Zn(II).