- The White Helmets (Arabic: الخوذ البيضاء ,القبعات البيضاء al-Ḫawdh al-bayḍāʾ / al-Qubaʿāt al-Bayḍāʾ), officially known as Syrian Civil Defence (SCD; Arabic: الدفاع المدني السوري ad-Difāʿ al-Madanī as-Sūrī), is a volunteer organisation that operates in parts of opposition-controlled Syria and in Turkey. Formed in 2014 during the Syrian Civil War, the majority of the volunteers’ activity in Syria consists of medical evacuation, urban search and rescue in response to bombing, evacuation of civilians from danger areas, and essential service delivery. As of April 2018, the organisation said it had saved about 114,000 lives, and that 204 of its members had lost their lives while performing their duties. They assert their impartiality in the Syrian conflict.
- Bismuth (Wikipedia)
Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs naturally, and its sulfide and oxide forms are important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery-white color when freshly produced. Surface oxidation generally gives samples of the metal a somewhat rosy cast. Further oxidation under heat can give bismuth a vividly iridescent appearance due to thin-film interference. Bismuth is both the most diamagnetic element and one of the least thermally conductive metals known.