Composition and Properties of Air

Hello, young explorers! It is well-known that air is everywhere though we cannot see it. It is the source of life on this planet. Let's explore the magical world of air, learn what it is made of, and discover why it is vital to life on Earth. But before we discuss its composition and properties, let us refresh your knowledge of this concept.

Q.1)   Air takes up _______ and has weight, which means it is a type of matter.

Q.2)   ________ is more important than water for survival.
Q.3)   Air is not a single substance but a _________ of gases. 

Answer to Q.1 - Space

Answer to Q.2 - Air
Answer to Q.3 - Mixture

 

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Why Do We Need Air?

Air is vital for life and contains oxygen, which we need to breathe and survive. The main reason plants, animals, and humans all need air is different:

For breathing: Our lungs absorb oxygen from the air to help function properly in our body.

For plants: They use carbon dioxide in the air to produce food by photosynthesis.

For Energy: Oxygen is crucial for burning fuels that enable the movement of vehicles to promote activities across the globe.

Air also acts as a protective shield from the harmful rays of the sun and maintains the perfect temperature for life on Earth.

Test your Understanding

 

1. What is the primary reason humans and animals need air to survive?

A) For protection from the sun

B) To obtain oxygen for breathing

C) To produce carbon dioxide

 

2. What would happen if there were no air on Earth?

A) Humans would float in space
B) Living organisms would not survive
C) It would always be nighttime

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The Composition of Air

Air is a mixture of gases that comes to envelop the Earth and gives support to life. Though this air appears to be transparent and weightless, it is comprised of several gases; each one plays an important role in maintaining a balance on our planet.

Here's a breakdown of Air's composition:

 

Major Gases in Air

1. Nitrogen (N₂):

• Nitrogen is a colorless, odorless gas making up 78% of air and is the most abundant gas present in the atmosphere.

• It is inert, i.e. non-reactive. It does not directly help in breathing but plays an important role in plant growth. It is used to manufacture ammonia and is a key part of fertilizers resulting in plant growth.

• It is released into the air from the nitrogen cycle, and the process involves some specific living organisms and the atmosphere.

• It is an essential component of protein present in the human body.

2. Oxygen (O₂):

• Oxygen makes up almost 21% of the air.

• This gas is most vital for respiration and combustion (burning).

• It helps the living beings to grow and reproduce

• It helps to turn food into energy for sustaining life on this planet.

• Oxygen is part of the Ozone layer that protects life on Earth from the harmful ultraviolet radiation that comes from the Sun.

3. Argon (Ar):

• Argon is the third most abundant gas taking up 0.93% of air.

• It is a noble gas, which means it doesn’t react easily and is popularly used in light bulbs and welding.

• It is a colorless, tasteless, and odorless gas.

• Though this gas is non-toxic and non-reactive, its higher levels can cause vomiting and nausea

• The medical use of Argon can be found in the endoscopic procedures involving the treatment of internal organs.

4. Carbon Dioxide (CO₂):

• Carbon dioxide accounts for only 0.04% and is a minor component of air.

• It can trap heat and is hence also called a greenhouse gas.

• Plants use Carbon dioxide for photosynthesis, and it also helps to regulate the Earth's temperature.

• It is produced through respiration, the burning of fossil fuels, and by the decomposition of organic materials.

• It is a food source for trees and helps in its growth.

 5. Other gases:

In addition to the above-mentioned gases, air also consists of water vapor, smoke, dust particles, and germs.

Test your Understanding:

1. Which gas in the atmosphere helps in blocking harmful ultraviolet rays from the sun?

A) Nitrogen

B) Oxygen

C) Ozone

D) Carbon Dioxide

 

 

A) 0.03%

B) 0.04%

C) 1%

D) 5%

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What Is the Percentage Composition of Gases in the Air?

Air is a mixture of various gases. Let’s break it down:

 

• Nitrogen (N₂): 78%

• Oxygen (O₂): 21%

• Argon (Ar): 0.93%

• Carbon dioxide (CO₂): 0.04%

• Other gases: Traces (like neon, helium, and methane)

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How Much Oxygen Is in the Air?

Oxygen makes up nearly 21% of the atmospheric air. While it is not the majority, it is what we most require to breathe and survive.

Is Our Air 100% Oxygen?

It is not 100% oxygen that we inhale through the air. If it were so, fires would burn uncontrollably, and this could be deleterious to us as well. The ratio of gases in the air keeps everything in check and order.

Do We Breathe In CO₂ (Carbon dioxide) or O₂ (Oxygen)?

We breathe in oxygen, O₂, in the air and expel carbon dioxide, CO₂. In our bodies, we are breaking down food to consume oxygen, and the by-product is the carbon dioxide emitted through breathing.

Which Gas Supports Burning?

Oxygen is a supporter of burning. The fire will quickly extinguish if there is no oxygen.

What Is Nitrogen Used For?

Even though nitrogen dominates most of the air, it is not utilized when breathed. It is, however, very important for:

• Plants: The availability of nitrogen from the soil aids in plant growth.

• Industry: Nitrogen is used to make fertilizers and to preserve food.

Which Gas Is Harmful in the Air?

Although most gases in the air are safe, some can be harmful. Some examples are:

• Carbon monoxide (CO): It is a toxic gas emitted from vehicles and fires.

• Sulfur dioxide (SO₂) and nitrogen oxides (NOx): This gas is emitted from factories, that can cause air pollution.

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The Properties of Air

Air surrounds us, though we cannot see it. It is a mixture of gases that fills space, weighing just like other things. Air can move and make wind, and it pushes on everything - we call that air pressure. It is also super stretchy, meaning we can squish or expand it. All these cool properties of air help us breathe, fly airplanes, and even enjoy fun things like balloons and bubbles.

                     

What Are the 10 Properties of Air?

Air is fascinating! Here are 10 cool properties of air:

1. Air takes up space: Even though we can’t see it, air fills balloons and our lungs.

2. Air has weight: It pushes down on us, which we call air pressure.

3. Air can move: That’s what creates wind.

4. Air can expand and contract: It grows bigger when heated and shrinks when cooled.

5. Air can flow: It moves around objects like water does.

6. Air has oxygen for life: Essential for breathing.

7. Air is invisible: You can’t see it, but you can feel it.

8. Air can dissolve in water: That’s how fish breathe underwater.

9. Air can carry sound: Without air, we couldn’t hear anything!

10. Air exerts pressure: This helps airplanes fly and keeps objects from collapsing.

                           

Test your Understanding:

1. Which of the following is a key property of air?

A) Air is visible and has no weight.

B) Air is invisible but has weight.

C) Air does not occupy space.

D) Air cannot exert pressure.

2. Which experiment demonstrates that air occupies space?

A) Filling a balloon.

B) Heating water in a beaker.

C) Melting ice.

D) Boiling salt water.

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What Properties of Air Make It Matter?

Air is a type of matter because:

• It has mass (it weighs something).

• It occupies space (it fills a balloon).

These properties prove that air is real and part of our physical world.

What Are the Characteristics of Air?

Air has some special features:

• It’s a mixture of gases, not just one gas.

• It’s odorless, tasteless, and colorless.

• It changes with temperature and pressure.

• It can carry moisture, leading to clouds and rain.

2. Approximately what percentage of the air is made up of oxygen?

A) 78%
B) 21%
C) 1%
D) 0.03%

4. What happens when air is cooled?

A) Air becomes lighter and moves upward.

B) Air shrinks as the particles slow down and move closer together.

C) Air disappears.

D) Air expands and becomes denser.

5. How do fishes and other marine animals breathe underwater?

A) They breathe the air that has dissolved in water

B) They breathe through oxygen cylinders

C) They can survive underwater without breathing

D) They breathe through their lungs