The word “atom” means indivisible in the original Greek. It was supposed to be the smallest indivisible object. “Object” meaning: tangible thing put before the senses. Atoms were supposed to be the smallest little LEGO blocks out of which everything was built. Western reductive materialism is largely predicated on seeing the world this way: A bunch of passive objects bouncing off of each other, except for us. Humans with sentience. Somehow we rose above the random chemical reactions of Universe to become intelligent. Now it is our right to arrange these LEGOs however we please (whether a God-given right according to the creationists or Sentience-given according to the scientists).
Does that story start to sound a bit thin when stated that plainly?
Prevailing scientific models no longer see atoms as indivisible objects, but rather a markedly complex system of interacting wavicles, forces, fields, and probability densities (wavicles = wave-particles which simultaneously have the properties of a wave and a particle).
We gave up indivisibility a long time ago. The current Wikipedia entry (excerpted below) about subatomic particle lists 100 of them without even getting far into anti-matter and anti-particles: