Atomic theory is the description of atoms, the smallest units of elements. The scientific evidence for the existence of atoms and its even smaller constituents is so vast that most people now consider the existence of atoms to be a fact and not just a...

Atomic theory," wrote Bernard Pullman, "is the most important and enduring legacy bequeathed by antiquity." Indeed, this the atomic theory provides a brilliant example of pure speculation which develops into a universally accepted scientific theory....

One of the points of dispute among early Greek philosophers was the ultimate nature of matter. The question was whether the characteristics of matter that can be observed with the five senses are a true representation of matter at its most basic level....

One of the points of dispute among early Greek philosophers was the ultimate nature of matter. The question was whether the characteristics of matter that we can observe with our five senses are a true representation of matter at its most basic level....

One of the points of dispute among early Greek philosophers was the ultimate nature of matter. The question was whether the characteristics of matter that we can observe with our five senses are a true representation of matter at its most basic level....

ancient philosophical speculation that all things can be accounted for by innumerable combinations of hard, small, indivisible particles (called atoms) of various sizes but of the same basic material; or the modern scientific theory of matter according...

This article focuses on the historical models of the atom. For a history of the study of how atoms combine to form molecules, see History of the molecule. In chemistry and physics, atomic theory is a theory of the nature of matter, which states that...