Question

describe in short an experiment that proves the atmospheric pressure occurs​

Answer 1

Answer:

Fill roughly one-third of a cup with water. Then, cover the mouth of the cup completely with a flat, hard cardboard. ... Thus we can demonstrate that air exerts pressure, because otherwise, the water would have fallen.

I hope my answer is helpful for you ✌️☺️

Answer 2

Answer:

Using your hand to keep it in place, turn the cup upside down. When you remove your hand, the the cardboard stays in place. One would expect that due to gravity, the water will fall, and even the cardboard will. Thus we can demonstrate that air exerts pressure, because otherwise, the water would have fallen.