The behaviour of matter and radiation on the atomic scale often seems peculiar, and the consequences of quantum theory are accordingly difficult to understand and to believe. Its concepts frequently …

In the two centuries since Dalton developed his ideas, scientists have made significant progress in furthering our understanding of atomic theory. Much of this came from the results of several seminal …

Antoine Lavoisier (1743-1794) restated this principle for chemistry with the law of conservation of mass, which "means that the atoms of an object cannot be created or destroyed, but can be moved around …

Chemistry is based on the modern atomic theory, which states that all matter is composed of atoms. Atoms themselves are composed of protons, neutrons, and electrons.

The most foundational chemistry idea of all is atomic theory. As we consider this theory in some detail we will identify the composition and mass of atoms, the variability of the composition of isotopes, ion …

Chemistry is based on the modern atomic theory, which states that all matter is composed of atoms. Atoms themselves are composed of protons, neutrons, and electrons.

Atomic theory has evolved from Democritus's early ideas to John Dalton's modernized postulates. Dalton proposed that all matter consists of indivisible atoms, which are identical for each element, …

Atomic theory provides a foundation for understanding chemical bonding, material science, nuclear physics, and quantum mechanics. It guides explanations for material properties, reaction …

Dec 16, 2025 · Philosophers Leucippus and his student Democritus proposed the concept of atomos, a Greek word meaning “uncuttable” or “indivisible.” They argued that if a substance were continuously …

Dec 23, 2025 · In psychology, atomism is a doctrine about perception. It holds that what human beings perceive is a mosaic of atomic sensations, each independent and unconnected with any other …