Gases. Nitrogen (N2) is the most prevalent naturally occurring gas, accounting for approximately 78 percent of the air. At around 21%, oxygen (O2) is the second most prevalent gas. Argon (Ar), an inert gas, is the third most prevalent gas on the planet. The other gases found in small quantities include carbon dioxide (CO2), hydrogen sulfide (H2S), ozone (O3), and a few others.
On Earth, there are three major sources of nitrogen: natural processes, industrial activities, and animals. Natural processes such as soil bacteria and fungi converting organic material into ammonia, which is then absorbed by plants, or removed by leaching into water, constitute the main source of nitrogen for non-industrial areas. In agricultural regions, however, large amounts of nitrogenous fertilizers are applied to stimulate growth of food crops. This leads to high levels of nitrogen in the soil and ocean, with consequences for other organisms that depend on these resources.
Industrial activities include combustion of fossil fuels (oil, natural gas, and coal) as well as industrial chemicals. The largest source of emissions of gases other than CO2 is probably oxides of nitrogen, from products used in chemical processes and materials treated with those products. Other significant sources include sulfur hexafluoride when produced by semiconductor manufacturers and hydrofluoric acid when produced by fluorine producers.
Nitrogen is by far the most prevalent gas in the Earth's atmosphere, accounting for approximately 78 percent of the mass of dry air. The second most prevalent gas is oxygen, which is found at quantities ranging from 20 to 21 percent. The remaining 2 to 3 percent is made up of other gases such as argon, carbon dioxide, water vapor, methane, and others.
Earth's Atmosphere: A Complete Guide (2017) by Peter H. Hess et al. states that nitrogen makes up over 99% of the atmosphere by volume. Oxygen accounts for only 0.12% while all the other gases combined account for just under 1%. That means that almost every molecule of nitrogen is surrounded by another molecule of nitrogen or oxygen depending on how you look at it. If you counted each atom of these other gases separately, they would amount to less than 0.01% of the total mass of the atmosphere.
The majority of nitrogen is found in the three chemical forms described below. Nitrogen is also a major component of ammonia, which is used as a fertilizer and fuels industry. Ammonia is produced by the Haber-Bosch process, which converts hydrogen into ammonia via a series of reactions with nitrogen compounds.
Gaseous Nitrogen: Gaseous nitrogen exists as molecules with two atoms of nitrogen joined together.
The lowest level is mostly made up of molecular nitrogen (N2). There is a layer of atomic oxygen above it (O). Helium atoms (He) are the most prevalent element at even greater altitudes. "The Earth's Atmosphere's Four Most Abundant Gases." ThoughtCo, accessed August. 2015.
Helium is the most abundant gas in the atmosphere. It makes up 25% of the atmosphere by mass. The other 75% is N2 and O2.
At the highest levels of the atmosphere, there is almost no air and so no way to detect any additional gases. But down on the surface, traces of many other gases are present in the air we breathe. Carbon dioxide, water vapor, ozone, and nitrous oxide are just a few of the gases that make up our atmosphere.
Heavier gases like hydrogen and helium do not usually play an important role in determining the density of the atmosphere. However, their presence in some regions of the atmosphere may affect the radiation coming from the planet or be involved in other chemical reactions.
Earth's atmosphere is very important because it allows life as we know it to exist. Without this protective blanket, all forms of life would be killed by solar radiation and other forms of damage caused by high-energy particles streaming through the air.
The sun heats Earth's surface which causes air inside Earth to expand.
The Gases in the Earth's Atmosphere Nitrogen and oxygen are by far the most prevalent; dry air is composed of around 78% nitrogen (N2) and 21% oxygen (O2). The other gases present in much smaller amounts include argon, carbon dioxide, hydrogen, ozone, and water vapor.
Living under a cloud-filled sky is a familiar experience for people around the world. Clouds are composed of liquid droplets of water or ice suspended in the air. They can be single particles or large assemblies of particles that cover most of the sky.
Clouds play an important role in determining the Earth's climate by acting as reflectors of solar radiation and agents of precipitation formation. They can also have harmful effects by blocking out direct sunlight and providing cover for heat absorption and retention. Changes in cloud patterns are therefore likely to have significant consequences for the Earth's climate and environment.
Clouds are classified according to their shape and structure. Flat clouds are those that are completely flat without any edges or angles. These may be formed from layers of liquid water or ice crystals that freeze into place.