How can you prove that air has mass?

Answer 1

Put the air in some sort of bottle and then heat the bottle... this is comparable to heating a deodorant spray can which then explodes. When you heat the bottle sufficiently, the bottle explodes due to the pressure build up from the higher energised molecules. These air molecules can only be able to do this if they exert pressure, and if they exert pressure, then they must have mass.

Answer 2

There are several ways to demonstrate that air has mass. Not all are feasible or practical for an at-home demonstration, but all can be ultimately demonstrated through scientific experimentation.

As another user suggested, wave your hand back and forth; the pressure exerted by wind resistance demonstrates that air has mass. That pressure is exerted by the work necessary to move the air out of the way of an object, overcoming the air's inertia and relocating its mass. But, there are other ways.

First and foremost, one may observe that all the laws of nature that are binding on other sorts of 'visible' matter are also binding upon air. For example, we addressed the inertia of air above, but air also has a temperature and can exchange heat with other objects. Air is acted upon by gravity, remaining close to the earth (rather than dissipating into space). These are all miscellaneous properties possessed by matter, and all demonstrate mass.

Further, air can simply be weighed on a scale. Really! In fact, this is a common chemistry experiment. First, weigh a container in which a vacuum has been created, and then weigh an 'empty' container containing only air. Then compare the numbers; the difference between the figures represents the weight (ie, the mass) of the air in the container.

There is another method that uses a vacuum to demonstrate the mass of air; the simplest barometer, using water or Mercury, can show that air has mass. A vacuum in a vertical tube will only raise water to a height of approximately 10 meters (less for heavier mercury), after which the water will no longer rise. This is because the mass of the atmosphere pushing down on the water will only force it up into the tube so long as the pressure created by gravity pulling on the mass of the atmosphere exceeds the pressure created by gravity pulling on the mass of the water in the tube. This crossover point occurs at around 10m (33 feet). Beyond 10m in altitude, the earth's atmosphere doesn't exert enough pressure to force the water any higher.

One final demonstration can show air's mass, also a staple of chemistry classes everywhere. When other substances react with the earth's atmosphere (air, more specifically oxygen in the air), the substances get heavier. Iron is a great example. A solid iron bar left on a scale to rust will slowly gain weight as it rusts. Unbelievable, but true. The reason is that the iron is slowly reacting with oxygen in the air, trapping it in iron oxide (rust). The rust slowly accumulates on the iron bar until its mass has increased enough to be measured.

There are other proofs, but these should be enough to convince even the most die-hard air denier that air has mass.

Answer 3

Air is matter and therefore has mass. Because we know that it's composed of mostly nitrogen, which has a mass of 14.01g per mole, air has mass.

You can weigh a balloon with nothing in it and then weigh it with air in it. The balloon will be heavier.

Answer 4

Air exerts pressure, so it must have mass. Air also has resistance, try sticking out your hand in a moving vehicle! If a balloon has mass, so does air. When blowing out a balloon, the air presses against the balloon. Air has mass.

Answer 5

Empty Balloon, Filled with air Balloon.

Get a yard stick, tape one balloon to each side, ones filled ones not.

Balance in the middle the yard stick will tip to the side with the filled air thus proving air has mass.

Answer 6

If it didn't have mass, gravity wouldn't affect it, so it wouldn't be attracted to the mass of Earth, so we'd have no atmosphere, so we wouldn't be talking about this question.

Answer 7

if you get a ballon without AIR and you mass it, it will have less mass than a ballon with AIR

Answer 8

We can take an inflattened balloon and weigh it on balance and then fill it with gas and weigh it again it will have weight.