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Date: 14-5-2020
957
Date: 3-6-2020
1038
Date: 23-8-2016
1564
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Aluminosilicate minerals are silicates when some of the Si4+ ions in silicates are replaced by Al3+ ions. For each Si4+ ion replaced by an Al3+ , the charge must be balanced by having other positive ions such as Na+, K+, and (Ca^{2+}) ions. Feldspar group and zeolites are typical aluminosilicates by this definition. Examples of minerals belong to the feldspar group include:
The alkali ions are held in place to balance the charges due to the presence of Al3+ ions instead of Si4+ ions. The Al3+ ions seem replace Si4+ ions in the chains of corner shared tetrahedra of SiO4 groups. However, the bonding between Al and Si can be different. Silicon atoms or ion tend to be bonded to 4 oxygen atoms in a tetrahedral fashion, but aluminum ions tend to be bonded to 6 oxygen atoms in an octahedral fashion.
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دراسة يابانية لتقليل مخاطر أمراض المواليد منخفضي الوزن
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اكتشاف أكبر مرجان في العالم قبالة سواحل جزر سليمان
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المجمع العلمي ينظّم ندوة حوارية حول مفهوم العولمة الرقمية في بابل
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