Answer:
Brownian motion
Explanation:
This immediately came to my mind when I read your question, I hope this came so some kind of use.
The experiment I thought of is the brownian motion. (this experiment refers to water particles)
In 1827, a botanist named Robert Brown observed pollen grains that moved randomly when in water. At the time, he just didn't know how to explain why the grains moved randomy and not in a particular direction.
Later in 1905, Albert Einstein explained that the grains moved randomly due to individual water molecules colliding with the pollen grains. This provided evidence that molecules did exist and contributed to the particle theory.
(Particle theory is a theory that explains properties of solids metals and gases. It also involves the arrangement and movement of particles, which can help with studying movement of air particles)
Hope this helps!
