من عجائب الكيمياء
🧪أن عنصر الصوديوم (Na) ينفجر عندما يلامس الماء،
🧪بينما عنصر الكلور (cl) يستخدم كسلاح كيميائي في الحرب العالمية الاولى،
🧪المدهش في الامر أنه عند دمجهما نحصل على المركب (Nacl) المستخدم
📫 www.tg-me.com/NationallGo
BY ناشيونال جيوغرافيك 🏞 | National G
Secure video calling is in high demand. As an alternative to Zoom, many people are using end-to-end encrypted apps such as WhatsApp, FaceTime or Signal to speak to friends and family face-to-face since coronavirus lockdowns started to take place across the world. There’s another option—secure communications app Telegram just added video calling to its feature set, available on both iOS and Android. The new feature is also super secure—like Signal and WhatsApp and unlike Zoom (yet), video calls will be end-to-end encrypted.
Traders also expressed uncertainty about the situation with China Evergrande, as the indebted property company has not provided clarification about a key interest payment.In economic news, the Commerce Department reported an unexpected increase in U.S. new home sales in August.Crude oil prices climbed Friday and front-month WTI oil futures contracts saw gains for a fifth straight week amid tighter supplies. West Texas Intermediate Crude oil futures for November rose $0.68 or 0.9 percent at 73.98 a barrel. WTI Crude futures gained 2.8 percent for the week.
ناشيونال جيوغرافيك from us