Eric is a science teacher. He teaches atmospheric science: climatology, meteorology, and aeronomy
The atmosphere is the layer of gases surrounding our planet. It is held by the gravity of the Earth, so it does not escape into outer space. Its function is to absorb the harmful rays of the sun. It also protects us from meteor impacts and other celestial debris that fall on our planet. It is also the cause of the weather.
The atmosphere is composed of different gases in different amounts. Its most abundant gases are nitrogen and oxygen which comprise 99% of the air. It follows by almost 1 percent account for argon and a very tiny amount of pollutants, greenhouse gases, and other gases.
The top 10 most abundant gases in the atmosphere are shown in the table and pie chart below.
Top 10 Most Abundant Gases of the Atmosphere, by Volume Percent
|Name of Gas||Formula||Volume Percent|
Volume Percent of Main Constituent of the Dry Air
What are the characteristics of these 10 gases? Let's find out below.
Nitrogen (N2), also called azote, is the most abundant gas in our atmosphere. It is an inert, diatomic compound. Its name comes from the Greek words “nitron” which means “native soda” and “genes” for “producer.” It is used to make fertilizers, nylon, nitric acid, ammonia, and explosives. Moreover, the air that half-empty your potato chip bag is actually nitrogen. It prevents the chips from oxidizing, which makes them go stale.
Nitrogen is essential to life and its compound nitrate (NO3) is needed to construct DNA, RNA, and amino acids. It is converted to nitrate through lightning storms and nitrogen-fixing bacteria. The bacteria capture atmospheric nitrogen to convert it to ammonia (NH3). The ammonia catalyzes biological oxidation and becomes nitrite (NO2) and nitrite undergoes another oxidation and becomes nitrate. Nitrate nourishes the soil and is absorbed by the plants. The plants convert it to amino acids. The animals cannot create their amino acids, so they consume the plants to gain the nutrients. When the organisms died, they decompose by bacteria and release ammonia and nitrogen back to the atmosphere. The nitrogen will capture again by bacteria and the process repeats.
Nitrate is also formed when lightning struck the diatomic nitrogen. The two atoms of nitrogen split and quickly combine with oxygen. Then, they bond with the water molecule in the cloud forming the nitrate. The nitrate will fall together with the rain, nourish the soil, and be absorbed by the plants.
Oxygen (O2) is a very reactive, diatomic gas. It easily combines with another element and is incorporated with many chemical compounds such as water (H2O) carbon dioxide (CO2). It is the cause of combustion. When the oxygen combines with the other molecule in the air, it results in burning.
Oxygen is released by innumerable plants, green algae, and cyanobacteria as a waste product of photosynthesis. It is needed and breathed by humans, animals, fungi, and other eukaryotic organisms to survive.
It can also form into three molecules of atoms, which is known as the ozone. The ozone layer is located above the clouds. It helps us to block the harmful ultraviolet radiation from the sun.
The amount of water (H2O) in the atmosphere may vary depending on the weather condition and location on the earth, and it is not always in the gaseous form — it can be also in the form of solid (such as ice and glaciers) and liquid form (such as ocean and river) naturally. In the tropical region, where the climate is warm, the water evaporates, so the humidity is high. In extremely cold areas, such as Antarctica, where the water freezes, and in the arid region such as the Sahara desert, water vapor in the air may be absent.
Most of the water is concentrated in the lower atmosphere. It is one of the four factors that influence the weather — the other factors are wind, temperature, and pressure. During the hot day, water on the surface of the earth is heated and evaporated becoming part of the atmosphere. Once the air is cooled to its dew point, it condenses to form clouds and precipitates back to earth in the form of rain and snow. Water can be also in the form of fog, drizzle, hail, frost, and dew.
Water vapor is an effective greenhouse gas and can contribute to global warming. Fortunately, it does not stay in the air for a long time, so we don't worry about it. It condenses and back to earth naturally, unlike carbon dioxide and methane that last for decades.
Water covers around 70% of the Earth’s surface. It is essential for life on Earth. Apart from drinking, people have many uses for it such as bathing, irrigation, cooking, washing, etc.
Argon (Ar) is a colorless, odorless, inert, nonreactive, noble gas. It comes from the Greek word “argos” which means “not working” or “lazy” due to its inability to combine with another element. It is the third most abundant gas in the dry atmosphere, at nearly one percent. However, it has no known environmental role. But in industry, it is used for the welding and the production of titanium.
5. Carbon Dioxide
Carbon dioxide (CO2) is an acidic, inert, inflammable chemical compound. It is the bubbles that you see in soda, beer, and wine. It is formed during fermentation, decaying organic waste and organisms, volcanic eruption, and burning organic material and fossil fuel. Furthermore, it is also produced and exhaled by humans, animals, fungi, and other eukaryotic organisms, and absorbs and utilize by plants during photosynthesis.
Carbon dioxide is a very important greenhouse gas. It absorbs many infrared wavelengths of the sun's light that gives heat to our planet. Too much greenhouse gas can cause global warming. Global warming can cause climate change, which is a serious threat to life on earth through extreme weather, and widespread flooding. And sadly, carbon dioxide lasts for many centuries in the air.
Like argon and other noble gases, neon does not react or combine with other elements. Neon is an inert, monatomic gas and is about two-thirds of the density of air. It is a colorless substance but exhibits a reddish-orange glow in vacuum tubes. It is commonly used in advertising signage, television tubes, lightning arrestors, and lasers.
Helium is named after the Greek god of the sun, Helios. It relates to the fact that it was discovered on the sun's corona and was believed to exist only in the sun before it was found on earth. This noble gas is odorless, colorless, and nonreactive. It has the lowest melting point (-272.2 °C) and boiling point (-268.9 °C) of the element.
Most of them are concentrated in the upper atmosphere because this gas is very light, so, it floats in the sky. This is the reason why we used it for filling balloons and airships. It is the second most abundant chemical element in the universe, however, it is rare on earth. Because of its lightness, gravity is not strong enough to hold on to it, so, it can escape into outer space.
Methane (CH4), also called marsh gas, is an odorless, flammable chemical compound. Methane is released by decaying organic waste and dead organisms, digestion of termites, and ruminants (animals with four-chambered stomachs such as cows, deer, sheep, and giraffes), and emits by volcanoes and vents in the ocean floor. It is the primary component of natural gas or the fossil fuel that we used for cooking and provides power to our motor vehicles.
Methane is the leading contributor to the greenhouse effect and global warming. It is a very dangerous gas and is 86 times more powerful than carbon dioxide. Fortunately, it can only last for 10 to 12 years, unlike CO2 that lasts for centuries.
Krypton (Kr) is produced by the fission of radioactive uranium. The concentration of Krypton at the North Pole is 30% higher than at the South Pole due to almost all the world's nuclear reactors and plants are located in the Northern Hemisphere.
Krypton is a colorless gas but glows purple at a high temperature and emits a very bright white light when inside an electric field. The white light that is released by flash photography and light bulbs are produced by krypton.
The word hydrogen (H2) is from the Greek “hydro” means “water” and genes for “forming” because it is one of the parts that make up a water molecule. It is the lightest chemical element in the periodic table so, like helium, it floats in the air and escapes into space. However, it does not use for filling balloons because it is combustible and can explode.
It is the most abundant element in the whole universe but rare in the earth's atmosphere. Most of them are bounded to many chemical compounds such as water and hydrocarbons. Its compounds are used in many industrial sectors, including glass, electronics, and metallurgy.
For each question, choose the best answer. The answer key is below.
- What is the most abundant gas in the atmosphere?
- 99 percent of the earth's atmosphere is comprised of _.
- nitrogen and oxygen
- oxygen and carbon dioxide
- What form of oxygen has three atoms of itself?
- What is the gas that uses to fill the balloon and airship?
- nitrogen and oxygen
- Atmosphere of Earth - Wikipedia
- Greenhouse Gas - Wikipedia
- Water Cycle | National Geographic Society
- nitrogen cycle | Definition & Steps | Britannica
- Noble Gas | Definition, Elements, Properties, Characteristics, & Facts | Britannica
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
© 2021 Eric Caunca
Misbah from The Planet Earth on March 01, 2021:
Thank you for sharing this informative article, Eric
Maybe it will help me when I give tuition class to my younger Brother
He is studying about Gases recently