Why is Air a Matter? (Explained)

Yes, air is a matter. It is a mixture of different gases, primarily nitrogen (78%), oxygen (21%), and traces of other gases like carbon dioxide, water vapor, and noble gases. 1 Matter refers to anything that occupies space and has mass, 2 and since air has mass and fills the space it occupies, it qualifies as matter.

Well, this was just a simple answer. But there are few more things to know about this topic which will make your concept super clear.

So let’s dive right into it.

Explanation: Why is air a matter?

Air is considered a form of matter because it possesses several fundamental properties of matter. Matter, in general, refers to anything that has mass and occupies space. 

Let’s examine why air meets these criteria:

  1. Mass: Air is composed of different molecules, mainly nitrogen (N2), oxygen (O2), carbon dioxide (CO2), and traces of other gases. 3 These molecules have mass and contribute to the overall mass of the air. Although individual molecules are very light, the vast number of them in a given volume of air adds up to a significant mass.
  2. Occupies Space: Air, like any other form of matter, takes up space. It fills the environment and occupies the volume it encompasses. When you move your hand through the air, you can feel its presence because it occupies the space your hand displaces.

Moreover, air exhibits other properties that are characteristic of matter:

  1. Compressibility: Air can be compressed or expanded under the influence of external forces. 4 The gas molecules in the air are relatively far apart, and when pressure is applied, they can be pushed closer together, reducing the volume they occupy. This property is essential in various applications, such as gas cylinders and air compressors.
  2. Fluidity: Air behaves as a fluid, meaning it can flow and take the shape of its container. 5 When you blow air, it moves and fills the available space, conforming to the shape of the container. This fluidity is due to the weak intermolecular forces between the gas molecules.
  3. Diffusion: Air particles exhibit the property of diffusion, meaning they tend to spread out and mix with other gases. This property allows for the dispersion of gases throughout the atmosphere, enabling the exchange of gases during processes such as respiration.

In summary, air is considered matter because it possesses mass, occupies space, can be compressed, behaves as a fluid, and demonstrates diffusion. These fundamental characteristics align with the definition of matter and classify air as a form of matter.

What is air made up of?

Air is primarily made up of a mixture of gases, with nitrogen and oxygen being the two most abundant components.

Here is a breakdown of the composition of air:

  • Nitrogen (N2): Nitrogen makes up approximately 78% of the Earth’s atmosphere. 6 It is a diatomic molecule composed of two nitrogen atoms bonded together (N2).
  • Oxygen (O2): Oxygen constitutes about 21% of the atmosphere. 7 Like nitrogen, it is also a diatomic molecule, consisting of two oxygen atoms bonded together (O2). Oxygen is vital for the survival of many organisms and is necessary for respiration.
  • Argon (Ar): Argon is the third most abundant gas in the atmosphere, accounting for about 0.93%. It is an inert gas and does not readily react with other substances. 8
  • Carbon Dioxide (CO2): Carbon dioxide is present in trace amounts, making up about 0.04% of the atmosphere. 9 10 It plays a crucial role in the Earth’s carbon cycle and is involved in processes such as photosynthesis and respiration.
  • Other Gases: Besides the major components mentioned above, air also contains various trace gases in smaller concentrations. These include gases such as neon (Ne), helium (He), methane (CH4), ozone (O3), hydrogen (H2), and water vapor (H2O). The exact composition of these trace gases can vary depending on location, altitude, and other factors.

It’s important to note that air can also contain suspended particles, such as dust, pollen, pollutants, and aerosols. These particles are not gases but are present within the air mixture.

Overall, air is a mixture of gases, primarily nitrogen and oxygen, with smaller amounts of argon, carbon dioxide, and trace gases.

Further reading

Is Fire a Plasma?
Is Fire a Gas?
Is Fire an Element?
Is Evaporation a Physical or Chemical Change?
Is Dissolving a Physical or Chemical change?

About author

Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. He is a founder of Pediabay and is passionate about helping students through his easily digestible explanations.

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  1. Climate Change, N. G. (2016, September 12). 10 interesting things about air – Climate Change: Vital Signs of the Planet. Climate Change: Vital Signs of the Planet. https://climate.nasa.gov/news/2491/10-interesting-things-about-air
  2. Austincc.edu https://www.austincc.edu/mreid/CHEM_1405_Chapter_2.PDF
  3. for Science Education, U. C. (n.d.). What’s in the Air? | Center for Science Education. What’s in the Air? | Center for Science Education. https://scied.ucar.edu/learning-zone/air-quality/whats-in-the-air
  4. Faa.gov https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/phak/media/06_phak_ch4.pdf
  5. Foundation, C. (n.d.). CK12-Foundation. CK12-Foundation. https://flexbooks.ck12.org/cbook/ck-12-middle-school-physical-science-flexbook-2.0/section/12.1/primary/lesson/pressure-in-fluids-ms-ps/
  6. UCLA-led study may explain the source of nitrogen in Earth’s atmosphere. (n.d.). UCLA. https://newsroom.ucla.edu/releases/source-of-nitrogen-in-earths-atmosphere
  7. Watson, A., Lovelock, J. E., & Margulis, L. (1978, December). Methanogenesis, fires and the regulation of atmospheric oxygen. Biosystems, 10(4), 293–298. https://doi.org/10.1016/0303-2647(78)90012-6
  8. Argon – Wikipedia. (2013, October 14). Argon – Wikipedia. https://en.wikipedia.org/wiki/Argon
  9. The Atmosphere: Getting a Handle on Carbon Dioxide – Climate Change: Vital Signs of the Planet. (2019, October 9). Climate Change: Vital Signs of the Planet. https://climate.nasa.gov/news/2915/the-atmosphere-getting-a-handle-on-carbon-dioxide
  10. Carbon Dioxide 101. (n.d.). https://netl.doe.gov/coal/carbon-storage/faqs/carbon-dioxide-101

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