ABSTRACT
A COMPOSITION OF THE ATMOSPHERE
1 Total atmosphere
Air is a mechanical mixture of gases, not a chemical compound. Table 1.1, illustrating the average composition of dry air, shows that three gases – nitrogen, oxygen and argon – account for 99.9 per cent of the air by volume. Moreover, rocket observations show that these gases are mixed in remarkably constant proportions up to about 80 km (50 miles).
