Invisible but indispensable

Air What constitutes air, anyway? We often hear things like: it smells good here, it stinks, dry air insulates well, or: we should keep an eye on the air pressure of our tires. But these remarks only deal with some of the properties of air. Air, on earth, is composed of 78 % nitrogen and 21 % oxygen. The remaining 1% of air is made up of a combination of noble gases, water vapor and carbon dioxide, which constantly vary […] Read more »