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Date: 29-3-2017
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Date: 7-7-2020
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Date: 15-6-2019
1066
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Here you are faced with one of the most irritating facts in chemistry at this level! When you work out the electronic structures of the first transition series (from scandium to zinc) using the Aufbau Principle, you do it on the basis that the 3d orbitals have a higher energy than the 4s orbital.
That means that you work on the assumption that the 3d electrons are added after the 4s ones. However, in all the chemistry of the transition elements, the 4s orbital behaves as the outermost, highest energy orbital. When these metals form ions, the 4s electrons are always lost first.
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"الرعاية التلطيفية".. تحسين جودة حياة المرضى هي السر
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العلماء الروس يطورون طريقة جديدة لإعادة تدوير النفايات البلاستيكية
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اختتام المراسم التأبينية التي أهدي ثوابها إلى أرواح شهداء المق*ا*و*مة
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