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Date: 9-10-2018
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Date: 19-10-2018
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Date: 19-10-2018
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Independently discovered in 1735 by Antonio de Ulloa and in 1741 by Charles Wood, platinum is named from the Spanish platina or "silver". The metal is classified as precious owing to its scarcity and commercial demand. It is very heavy and silvery white and is used in laboratory instruments, jewelry, medical and dental items, and electrical contacts. Because it is immune to air oxidation the metal is often found in native form in nature. It is sometimes found in a rare, naturally occurring alloy, platiniridium. Naturally occurring platinum is a mixture of six non-radioactive isotopes.
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كيف تساهم الأطعمة فائقة المعالجة في تفاقم مرض يصيب الأمعاء؟
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مشروع ضخم لإنتاج الهيدروجين الأخضر يواجه تأخيرًا جديدًا
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المجمع العلمي يختتم دورته القرآنية في فن الصوت والنغم بالطريقة المصرية
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