This is from an amazing explanation of the airfoil by Bartosz Ciechanowski – one of many physics / engineering demonstrations on his (highly recommended) website.
A cube of air with sides of just 1cm would contain around 25 quintillion, or 2.5×10^19 particles.
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At room temperature the average speed of a particle in air is an astonishing 1650km/h (about 460 m/s), which is many times higher than even the most severe hurricanes.
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Each particle experiences roughly ten billion collisions per second.
Bartosz Ciechanowski – Airfoil
This is how air pressure works, and why (for example) air behaves in particular ways before an airfoil even reaches it.
For comparison, a cubic centimeter of water contains something like thirty-three sextillion molecules (3.3 x 10^22), colliding at – at least as estimated by Richard Feynman – one hundred billion (10^14) times per second.