Greek philosopher Leucippus of Miletus of Turkey, proposed the first atomic theory back in 500 BCE, noting the existence of an eternal empty space in which small indivisible particles, called atoms swirl in constant motion. His student, Democritus of Abdera, concluded that the universe is made of only two things: the Void (space) and Being (matter), are made up entirely of infinitesimal, fundamental particles called atomon. Although both ideas sound modern they were did not a scientific theory, yet based on observation and experiment. John Dalton proposed the first scientific atomic theory in 1803, based chemical experimentation and retained the word “atom” describing the small particles of all elements and compounds composition.
Leucippus of Miletus
- Atomic theory – Wikipedia
In chemistry and physics, atomic theory is a scientific theory of the nature of matter, which states that matter is composed of discrete units called atoms. … 19th century chemists began using the term in connection with the growing number of irreducible chemical elements.
- Atomic Theory I | Chemistry | Visionlearning
Atomic Theory I: Cathode Rays, Electrons and the Nucleus …. Ernest Rutherford, a former student of Thomson’s, advanced atomic theory yet another notch.
- Atomic Theory – Infoplease
A theory of the structure and behavior of atoms has taken more than two millenia … advanced enough to allow scientists a glimpse of the atom’s constituent parts: …
- Dalton’s atomic theory (article) | Khan Academy
Key Points. Dalton’s atomic theory was the first complete attempt to describe all matter in terms of atoms and their properties. Dalton based his theory on the law of conservation of mass and the law of constant composition. The first part of his theory states that all matter is made of atoms, which are indivisible.
- 2.2 Evolution of Atomic Theory – Chemistry
In the two centuries since Dalton developed his ideas, scientists have made significant progress in furthering our understanding of atomic theory. Much of this …