what is atomic theory?
It is the scientific theory that matter is composed of particles called atoms.
Atomic theory
 is the scientific theory that matter is composed of particles called atoms.
who came up with the theory of continuous matter Pre-Socratic Greek philosophers Leucippus and his pupil Democritus
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Atomic theory [SEP] Introduction
Atomic theory is the scientific theory that matter is composed of particles called atoms. Atomic theory traces its origins to an ancient philosophical tradition known as atomism. According to this idea, if one were to take a lump of matter and cut it into ever smaller pieces, one would eventually reach a point where the pieces could not be further cut into anything smaller. Ancient Greek philosophers called these hypothetical ultimate particles of matter "atomos", a word which meant "uncut". In the early 1800s, the scientist John Dalton noticed that chemical substances seemed to combine and break down into other substances by weight in proportions that suggested that each chemical element is ultimately made up of tiny indivisible particles of consistent weight.