The wind is air in motion. The air is a gasses' mixture: nitrogen (78%), oxygen (20%) and other gasses called noble gasses (2%). These gasses are colourless, it means that they don't have any colour and that's why we can't see them.

We feel the air because it is a fluid, such as water, and it has density. The air's density is too low, its molecules are very separated. When air moves, or someone moves, most of the molecule's particles crash into that person, pushing him/her. The strength of the air depends on its speed.

The air moves as a result of its density's changed, due to the temperature. When the temperature increases, the air turns less thick and its particles separate, becoming lighter, then it starts to go up toward the clouds. But in the rise, it gets cold and its particles move closer together again, turning the air thicker and making it goes down in order to warm up once again.

Mara Gambero, 4 ESO A1

IES Albaytar, 2021