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Date: 15-6-2019
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Date: 13-3-2017
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Date: 25-6-2020
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The reactivity of the metals
In general, the metals are moderately reactive and combine to give binary compounds when heated with dioxygen, sulfur or the halogens (e.g. reactions 1.1–1.3), product stoichiometry depending, in part, on the available oxidation states (see below).
(1.1)
(1.2)
(1.3)
Most d-block metals should, on thermodynamic grounds liberate H2 from acids but, in practice, many do not since they are passivated by a thin surface coating of oxide or by having a high dihydrogen overpotential, or both. Silver, gold and mercury (i.e. late, second and third row metals) are, even in the thermodynamic sense, the least reactive metals known. For example, gold is not oxidized by atmospheric O2 or attacked by acids, except by a 3 :1 mixture of concentrated HCl and HNO3 (aqua regia).
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5 علامات تحذيرية قد تدل على "مشكل خطير" في الكبد
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تستخدم لأول مرة... مستشفى الإمام زين العابدين (ع) التابع للعتبة الحسينية يعتمد تقنيات حديثة في تثبيت الكسور المعقدة
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