Atomism, the start of ‘real’ chemistry. It is the idea that the natural world is composed of fundamental, indivisible partices called atoms.The Greek philosphers Democritus and Leucippus and the Indian philospher Kanada came up with these ideas around the same time, 400BC. The claims were controversial as both philosphers lacked the empirical evidence needed to back up their claims. Their claims were even opposed by Aristotle.
The word atom comes from the Greek word atomos which means ‘uncuttable’.