Oxygen in the air. The percentage of oxygen in the air can be measured by passing a known volume of air over hot copper, and measuring the decrease in volume as the oxygen reacts with it. Here are the equations for this reaction: copper + oxygen â copper oxide. 2Cu + O2 â 2CuO.
Get ready - World Backup is March 31st! About World Backup Day is a day for people to learn about the increasing role of data in our lives and the importance of regular backups.
Amazon Prime Day. Posted Jul 6, 2015 by Catherine Shu (@catherineshu) Black Friday, the annual shopping extravaganza which brought in more than $1.5 billion in online sales alone last November, is arguably the single most important day for retailers in the U.S. Now Amazon wants to steal its thunder with Prime Day.