2. Air: The Invisible Matter

Imagine air like a big group of tiny, invisible particles floating around us. Even though we can't see them, these particles have a few special qualities that make air a kind of matter.

Matter means anything that has mass and volume (takes up space). Air has mass because it's made up of lots of these tiny particles. And when these particles get together, they fill up space – just like when you blow up a balloon, you're filling it with air.

The closer we are to Earth, the more air is pressing down on us because there are more air particles above. This is why air pressure is higher at sea level and lower at higher elevations, like the top of a mountain.

1. Air Occupies Space:

We can confirm that air occupies space because when air is blown, it fills the empty area. The more air you blow, the more it will expand, proving that air occupies space2. 

Vid. 2.2 Air has weight5

Fig. 2.3 Air Pressure is lower on mountains and higher on the surface of earth

Let’s watch this video12 to see a demonstration to prove air exerts pressure:

There is air all around us and across the entire planet.  It surrounds us in every direction.  Although we cannot see the air, as it moves, we can sense its presence.

Moving air is called wind.

Gently blowing air is a breeze. 

There is a layer of air encircling our planet. The term "atmosphere" refers to this layer, which rises many kilometres above the surface of the earth. The air becomes more scarce as we move higher in the skies6.