Why is oxygen the commonest gas at the Earth's crust?

Answer 1

Well, it's not only the most common gas, but the most abundant element in the

earth's crust as well. This may be because 70% of the earth's surface is covered

with water - H2O. So there is the potential for lots of metal oxides.

Also consider the great amount of silicate matters - sand, clays, all gemstones,

granites and basalts... all silicates, which means silicon and oxygen (silicon is the

second most abundant element in the earth's crust).

So we have oxides, hydroxides, carbonates, sulfates, nitrates... all bond with oxygen. Oxygen is looking for two more electrons to complete its outer shell, so

there are many bonding possibilities.

Answer 2

Oxygen is the most abundant gas in Earth's crust because it is highly reactive and readily combines with other elements to form oxides. Additionally, oxygen is constantly being produced through processes like photosynthesis in plants, contributing to its prevalence in the atmosphere.