Where does the word atom come from and who first used this word?
Around 2,500 years ago this Greek dude name Democritus was sitting around just thinking. He was thinking about cutting stuff up and came up with the idea that there must be a point where you could no longer cut something any smaller. He named the atom after the Greek word atomos, which means that which can't be split. The cool part is that he was right, well 90% right.
We can split atoms, but if you split an atom it becomes something else. An atom is the smallest unit of a particular kind of material. For example if you cut a gold block into smaller and smaller pieces you would eventually be left with one gold atom. If you cut that atom into pieces you don't get smaller pieces of gold, you get protons, neutrons and electrons, which can be rearranged into something completely different.
Imagine how you would feel if you thought of an idea that took 2,400 years before it was proved right! Talk about being ahead of the times! There is a nuclear physics institute in Athens, Greece named after Democritus. Think about that, how it would feel to have people naming stuff after you thousands of years after you did your work!
Brian Kross, Chief Detector Engineer (Other answers by Brian Kross)