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.
Why do we celebrate world health day. The World Health Organization (WHO) sponsors the celebration of World Health Day on April 7 every year. the First World Health Assembly held by the WHO in 1948 declared that it would celebrate April 7 as World Health Day to mark the founding the WHO as well as to ensure that health concerns are highlighted too.