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.
Jul 06, 2015. July 15 is Amazon's Prime Day, a day the company has created to boost Amazon Prime membership, offering perks like wildly discounted items. Amazon claims there will be more deals on Prime Day than on Black Friday, the traditional shopping day after Thanksgiving where stores open at predawn hours with deep discounts.