if atoms are too small to see, how do we know atoms exist? And who discovered atoms?

Question

This was a real question by my 6yo. She asked what was made of atoms. I said everything, but they’re too small to see. “Oh, microscopic!” “Well, smaller actually.” “How do people know they exist? And what’s the name of the person who discovered them?”

Marked as chemistry cause that’s how ill-equipped I am to answer this question. Is it chemistry? Or should I have said physics?

In: 4

Answer 1

Early experiments in physics led to the precursor of the standard model

https://en.m.wikipedia.org/wiki/Rutherford_model