How do you explain that a gas has mass?

Question

We know how to measure the gas but how do you explain a gas has mass when some are lighter then air.

Answer 1

Because it exists! ALL things have mass, even if it's an incredibly small amount--from the air we breathe to an electron orbiting the nucleus of an atom.

In short, all things that exist in the universe have mass. If there is no mass, it exists only in imagination or theory.

Answer 2

A common sense explanation is what you are looking for. You first need to understand vacuum (the absence of pressure). A classic example of a vacuum is when you heat an open glass bottle and then place a round flexible object like a rubber ball just larger than the bottle opening over the bottle opening. When the remaining warm air in the bottle cools, the rubber ball is pulled partly or completely into the bottle. The cooling of the air in the bottle reduces the internal pressure, which is known as a partial "vacuum" and the higher pressure outside the bottle pushes the ball into the bottle.

If the air outside the bottle did not have pressure, the ball would not have been pushed into the bottle.

Air pressure is caused by the cumulative mass of the the gases in the air stacked all the way up in the earth's atmosphere. We know those gases have mass because they create this atmospheric pressure.

Answer 3

As long as you have molecules in a substance, whether it is solid, liquid or gas...it has mass. The only thing that doesn't has mass is pure empty space...with no atoms. Helium has mass, even though it is lighter than air. The mass can be calculated based on the atomic weight of the atoms that make up the substance....

Answer 4

Being lighter than air only means that the density of the gas is less than the density of air.

Every form of matter is composed of atoms, and those atoms have mass. So, all gases have mass.

Answer 5

well, the molecules in the gas all have a mass which is stated on the periodic table and some of those molecules could be lighter than all the molecules of air

Answer 6

I think having mass means having weight and occupying space, and gas meets this definition, even though you can't see it. Also mass can have any shape.

Answer 7

pounds per square inch.