What Are the Main Components and Properties of Air?
The world we reside in is covered with air, called the atmosphere. Our atmosphere is composed of several gases. The gases it contains are:
Nitrogen
Oxygen
Argon
Carbon Dioxide
Neon
Helium
Hydrogen
Ozone, etc.
The most important gases are Oxygen, Nitrogen, and Carbon Dioxide. Air also contains water vapor and dust particles.
By volume, 78.084% of N2, 20.946% of O2, and 1% of trace gases together; these gases make the atmosphere. Trace gases are lesser in volume, but they are essential to us. The following diagram shows the constituents of air.
(ImagewillbeUploadedSoon)
What is the Composition of Air?
What do we take in for survival? We intake the oxygen. However, the air we breathe doesn’t contain oxygen only; it has a composition of several gases. The characteristics of these gases are:
Nitrogen & oxygen are present in bulk in the atmosphere.
Carbon Dioxide, Helium, Ozone, Argon are present in a lesser amount.
Minute dust particles are also present in the atmosphere.
Plants require nitrogen for their survival, which they can’t take direction, so they take CO2 from the atmosphere.
Therefore, bacteria present in the soil and the roots of plants take N2 and convert it into the form that is usable for plants.
Nitrogen is the plenteous gas in the atmosphere. Now, we will talk about other essential gases.
Oxygen
Oxygen is the second most copious gas in the air.
During photosynthesis, plants release oxygen into the atmosphere.
Humans and other living creatures take in oxygen for their survival.
Carbon Dioxide
Carbon dioxide is another essential gas in the atmosphere after N2 and O2.
Green plants utilize carbon dioxide (CO2) to prepare their food and release O2 into the atmosphere.
Point to Ponder
The amount of carbon dioxide expelled by humans or other living beings appears to be equivalent to the amount used by the plants, thereby making an exact balance in the atmosphere. However, this statement doesn’t maintain verity, do you know why?
If We Talk About the Below-Mentioned Factors
Industries
The burning of fossil fuels
Release of carbon dioxide by living beings.
The continuous discharge/emission of carbon dioxide is producing (creating) an imbalance in the atmosphere. That’s why the above statement is wrong.
Chemical Composition of Air
The table lists the chemical composition of air:
The gases mentioned in the table are also known as the Principal Gases of Air.
Air and Its Properties
Air has the following properties:
Air takes up volume.
Air takes up the volume of the container it is kept in.
Air has mass/weight.
Take a balloon, measure its weight. Now, fill another balloon with air and measure its weight. You will note a difference in their weights.
Air is affected by altitude/height.
The higher we go, the lower is the air pressure. Everest climbers use oxygen tanks because, at higher altitudes, the oxygen becomes thin. These tanks help climbers breathe normally.
Air is affected by temperature.
Higher is the temperature of the air, the faster the motion of air molecules.
Air exerts pressure in all directions.
On shaking the cold-drink bottle and removing its cap, carbon dioxide comes out with pressure and spreads in all directions.
Air is compressible.
Carbon dioxide inside the cold-drink bottle comes out with pressure on removing the cap of the bottle.
The Table Below Shows the Properties of Air
Did You Know?
The troposphere, the lowest layer of the Earth's atmosphere, contains three-quarters of all air. Air is a combination of gases, the majority of which are found in nature.
Air also includes a large quantity of man-made air pollutants, including some that are dangerous to breathe and others that contribute to global warming.
Water in all three phases (liquid, solid, and gas), as well as solid particles known as aerosols, are found in the troposphere.
FAQs on Air Composition Properties Explained
1. What is the standard composition of gases in the Earth's atmosphere?
Air is a mixture of several gases. The approximate composition of dry air by volume is:
- Nitrogen (N₂): 78.08%
- Oxygen (O₂): 20.95%
- Argon (Ar): 0.93%
- Carbon Dioxide (CO₂): 0.04%
- Trace amounts of other gases like Neon, Helium, Methane, and Krypton.
The amount of water vapour can vary significantly from 0% to 4% depending on location and climate.
2. What are the key physical properties of air?
Air, although invisible, has several distinct physical properties. The most important ones are:
- It occupies space: An empty glass is actually full of air. You can prove this by inverting it in water.
- It has mass: A balloon filled with air weighs more than an empty balloon.
- It exerts pressure: The weight of the air above us creates atmospheric pressure. This pressure is exerted in all directions.
- It is compressible: You can squeeze a large amount of air into a small container, like a bicycle tyre.
- It supports combustion: The presence of oxygen in the air is essential for burning to occur.
3. What is the importance of oxygen in the atmosphere?
Oxygen is the second most abundant gas and is vital for life on Earth. Its primary importance lies in two key processes:
- Respiration: Almost all living organisms, including humans and animals, use oxygen to breathe. During respiration, oxygen helps break down food to release energy.
- Combustion: Oxygen is necessary for burning. No fire can exist without a supply of oxygen. This property is used in everything from lighting a candle to fuel combustion in engines.
4. What are the main properties of Nitrogen, the most abundant gas in air?
Nitrogen (N₂) makes up about 78% of the air. Its key properties are:
- It is a colourless and odourless gas.
- It is largely unreactive or inert, which means it does not easily take part in chemical reactions. This property makes it useful for packaging foods to prevent spoilage.
- It does not support combustion, effectively diluting oxygen and controlling the rate of burning on Earth.
- While inert in its gaseous form, nitrogen is a crucial component of proteins and DNA in living organisms, made available through the nitrogen cycle.
5. What are aerosols and how do they impact our environment?
Aerosols are tiny solid or liquid particles suspended in the air. Examples include dust, pollen, sea salt, and smoke from fires or pollution. They have a significant impact on the environment by:
- Influencing weather: Aerosols act as condensation nuclei, which means water vapour collects on them to form clouds, leading to rain.
- Affecting climate: They can scatter sunlight back into space, causing a cooling effect, or absorb it, which warms the atmosphere.
- Causing pollution: Particulate matter from industrial and vehicle emissions can be harmful to human health when inhaled.
6. Why is the atmosphere composed of 78% nitrogen and not another gas?
The high concentration of nitrogen in the atmosphere is due to its chemical stability. The nitrogen molecule (N₂) is held together by a very strong triple bond, making it largely inert and unreactive. Over billions of years, while more reactive gases like oxygen were consumed in geological and biological processes, nitrogen was released by volcanic activity and remained in the atmosphere, gradually accumulating to become the most abundant component.
7. How is the carbon dioxide present in the air essential for life?
Although carbon dioxide (CO₂) makes up only about 0.04% of the air, it is crucial for life on Earth. Its primary role is in photosynthesis, the process by which green plants use sunlight, water, and CO₂ to create their food (glucose) and release oxygen. This process forms the foundation of most food chains. Additionally, CO₂ is a key greenhouse gas that traps heat in the atmosphere, helping to maintain a warm and habitable temperature on Earth.
8. What is the fundamental difference between air and wind?
The difference lies between a substance and its motion. Air is the mixture of gases that constitutes the Earth's atmosphere. It is the 'stuff' that is all around us. Wind, on the other hand, is simply the movement of this air. It is caused by differences in atmospheric pressure, where air moves from a high-pressure area to a low-pressure area.
9. If nitrogen is essential for life, why can't most organisms use it directly from the air?
Most organisms cannot use atmospheric nitrogen because of the strong triple bond holding the two nitrogen atoms together in the N₂ molecule. This bond is very difficult to break, making the gas highly unreactive. Life forms depend on a process called nitrogen fixation, where certain bacteria in the soil and lightning strikes provide the energy needed to break this bond and convert atmospheric nitrogen into usable compounds like ammonia and nitrates, which plants can then absorb.
10. How does the composition of air change as we move to higher altitudes?
While the percentage composition of gases like nitrogen (78%) and oxygen (21%) remains relatively constant up to an altitude of about 80-100 km, the density of the air changes dramatically. As altitude increases, the air becomes 'thinner,' meaning there are fewer air molecules, including oxygen, in the same volume of space. This is why mountaineers need supplemental oxygen at high peaks. Above the lower layers, the concentration of lighter gases like helium and hydrogen becomes more significant.
