When it comes to the word Atom, we have to go to ancient Greece of 400 B.C. There was a brilliant philosopher named Democritus, and he proposed the Greek word Atomos, which means uncuttable. And so as he explained, all matter was eventually reducible to discrete, small particles or Atomos.
Atoms are made of tiny particles called protons, neutrons, and electrons.
It is hard to grasp just how small the atoms that make up your body are until you take a look at the sheer number of them. An adult is made up of around 7,000,000,000,000,000,000,000,000,000. ~ Wikipedia
How many times can you split an atom? Forever. ~ Norman Bliss