A hydrogen molecule model
In the alley, you are walking through you can see two low columns, each with a blue dot on top. Those dots represent the nuclei of hydrogen atoms that form an H2 molecule.
How it works
Every atom consists of a nucleus and an electron cloud which surrounds it. Almost the whole mass of every atom is located in the nucleus. Hydrogen nuclei in an H2 molecule is 0,074 nm apart; our model is over 500 billion times larger than the actual molecule. The linear scale of the nucleus size and distance has been maintained. This demonstrates how uneven mass distribution in the matter is.
As late as the early 20th century some scientists didn’t believe atoms existed, they included Wilhelm Ostwald or Ernst Mach. The atomic and molecular structure were elucidated thanks to the quantum the theory developed in the first three decades of the 20th century.