How Much Do You Know About the Air We Breathe?


By: J. Reinoehl

6 Min Quiz

Image: shutterstock

About This Quiz

Hey, science addicts! Let’s see if you really know what you’re breathing! Do you know what it’s made out of? You have heard of air pressure, but do you really know what it is? What keeps air from floating into space?

If you can answer these questions or if you want to learn the answers to these questions, this is the quiz for you!

Air in its purest form is colorless and odorless. In fact, smells that are traveling through the air can warn us when something is dangerous just as easily as they can get our bodies and stomachs ready to eat dinner.

Unlike water, light passes easily through air, allowing us to see better than we would if we lived in a watery environment. Air also has a very small refraction index and doesn’t bend the light the way water does. Even rainbows, which split light apart, are caused by water droplets found in the air and not the air itself.

There is a lot more to air than just “breathe in … breathe out …” This “How Much Do You Know About the Air We Breathe?” quiz is here to find out what you know about this important substance. Show us you know what part of air plants need to make food and then challenge your friends to beat your score!

At standard room temperature and pressure, air is considered to be in which state of matter?



Which two of the following elements make up most of the air we breathe?

Only 1% of the air we breathe contains other molecules such as carbon dioxide, hydrogen and neon.


What percentage of air is nitrogen?

“‘I don’t like this,’ his brother told him as they walked down the stairs. ‘You don’t like anything. I’ve heard you complain about the air.’ ‘It irritates me when it whistles.’” –G. A. Aiken, A Tale of Two Dragons


Which percentage of air is oxygen?

Although oxygen gas (O_2) is colorless and odorless, oxygen is light blue when it is a liquid or solid. By mass, oxygen is the third most abundant element in the universe.


Air holds tiny particles called what?

“I love the feeling of the fresh air on my face and the wind blowing though my hair.” –Evel Knievel


Sometimes air contains pollen that can cause which aliment?

The forget-me-not has the smallest pollen grain at 0.006 mm. Wind-distributed pollen grains can be up to 0.1 mm in diameter.


What is smog?

“A man is not expected to love his country… Yet, our country, seen through the mists of smog, is curiously lovable in somewhat the way an individual who has got himself into an unconscionable scrape seems lovable—or at least deserving of support.” –E. B. White


Respiration in animals is what?

Respiration is basically an exchange of gases that involves energy production. In animals, oxygen is the required gas and carbon dioxide is the waste gas.


Respiration in plants is what?

“Oh, thou are fairer than the evening air clad in the beauty of a thousand stars.” –Christopher Marlowe


What is humidity?

As relative humidity approaches 100%, clouds form. Eventually, the air can hold no more water and rain occurs.


What is another name for the air surrounding the earth?

“The atmosphere, the earth, the water, and the water cycle—those are good things. The ecosystems, the exosphere—those are good gifts. We have to regard them as gifts because we couldn’t make them. We have to regard them as good gifts because we couldn’t live without them.” –Wendell Berry


The density of air changes based on which of the following

Density is the mass of an object divided by its volume. Since volume changes with altitude and temperature and mass changes with humidity levels, the density of air is highly variable.


In order to make food and perform photosynthesis, plants need sunlight, water and which of the following gases found in air?

“…Equal rights, fair play, justice, are all like the air: We all have it, or none of us has it. That is the truth of it.” –Maya Angelou


What is the air pressure at sea level?

Atmospheres (atm) are only one unit used to express air pressure. Inches (or millimeters) of mercury, millibars, pounds per square inch, dynes per square centimeter and kilopascals are also used.


What is the relative humidity right before it rains?

“The choking humidity makes amphibians of us all in Bombay, breathing water in air; you learn to live with it, and you learn to like it, or you leave.” –Gregory David Roberts


The air around the earth protects the earth from which space objects?

According to NASA, meteoroids smaller than around 82 feet across pummel the earth each day but burn up quickly as soon as the hit the part of the earth’s atmosphere called the mesosphere. In order to reach the earth (and do minor damage) a meteoroid must be between 82 feet and ½ mile wide, but this only happens about once every 2000 years. Anything over ½ mile would be catastrophic.


What molecule with formula O3 protects us from ultraviolet rays?

“I think we learn slowly as a group, but we learn. The ozone layer is still there.” –Eden Robinson


What does hot air do?

In 1783, a fabric bag filled with hot air was released, and it was discovered that hot air rises. This led to the invention of the hot air balloon.


Why doesn’t the air around the earth float off into outer space?

“My dream is to have a house on the beach, even just a little shack somewhere so I can wake up, have coffee, look at dolphins, be quiet, and breathe air.” –Christina Applegate


How fast was the fastest recorded gust of wind on Earth?

For comparison, Hurricane Katrina (2005) reached speeds of 175 mph, and Hurricane Allen (1980), the strongest recorded hurricane, was 190 mph. The fastest tornado recorded was an F5 in 1999 that reached 318 mph.


What does air pressure mean?

“The scientist states that pressure is exerted outwards in all directions equally, whereas natural pressure (e. g. air pressure) is exerted inwards from all directions equally." –Viktor Schauberger


Microbial organisms found floating in the air are called what?

Microbial organisms that float in the air do not fly. They do travel long distances using wind and rain. The bacteria released when a person sneezes would be considered bioaerosols.


What does AQI stand for?

“It’s kind of a shock to your skin—changing climates. It’s new water and new air quality.” –Shay Mitchell


Which of the following is another term for atmospheric pressure?

In space, the barometric pressure is zero. Rising and falling barometric pressure is a good indicator for storms.


As altitude increases, air pressure?

“All flight is based upon producing air pressure. All flight energy consists in overcoming air pressure.” –Otto Lilienthal


Which of the following would you use to measure humidity?

You can make a hygrometer using two thermometers. One should be open to the air and the other should have the bulb covered by a wet cloth. To determine the humidity, you make a comparison between the two temperatures.


What is the minimum speed the winds in a hurricane must travel?

“…Persons who have never witnessed a hurricane… Can scarcely form and idea of their terrific grandeur. One would think that not content with laying waste all on land, it must needs sweep the shallows quite dry to quench its thirst.” –John James Audubon


Which of the following is caused by overbreathing and can make you pass out from low carbon dioxide levels?

Medical conditions such as stress and anxiety, heart problems, pneumonia and pregnancy can cause people to breathe more rapidly and hyperventilate. Breathing into a bag or holding your breath can help your body regain the carbon dioxide it needs to keep it in balance.


About how thick is the atmosphere surrounding the earth (from the Earth’s crust to the outer edge of the exosphere)?

“…One of my first memories is of sharing my worry with [my dad] about the space shuttle poking holes in the atmosphere and letting out all the Earth’s air.” –Brent Weeks


The layer of atmosphere closest to the earth is called what?

The troposphere extends up from the surface of the earth for about 5-9 miles. This layer contains the densest air.


If the AQI is over 100, what does it mean?

“Air pollution is my biggest concern right now. Maybe because I live in Beijing, and in this city, we have such severe challenges due to bad air quality. It has affected our daily lives and health. I do not go outdoors because of it.’” –Li Bingbing


What is the name of a device you could use to measure wind speed?

The anemometer was first developed in the middle of the 1400s. In cold conditions, anemometers must be internally heated to prevent icing and ensure accuracy.


What is the air temperature below which water droplets begin to condense called?

“Be still, sad heart, and cease repining; behind the clouds the sun is shining; thy fate is the common fate of all, into each life some rain must fall...” –Henry Wadsworth Longfellow from An April Day


What is it called when light is refracted through the air and causes you to see a pool of water down the road in front of you?

The mirage effect occurs because the surface (like the desert sand or a road) is much hotter than the air above it. Light bends differently as it moves through different temperatures of air. The bent rays cause your eyes to see the blue sky in that area, which you perceive as water.


What is the name of the scale used to measure the severity of a tornado (it has recently been “enhanced”)?

“Today, the technology is there to give early and normally ample warning when a powerful tornado approaches. When a tornado strikes, all of us are at risk” –Spencer Bachus


Explore More Quizzes

About HowStuffWorks Play
