Search results
- DictionaryA·tom·ic the·o·ry/əˈtɑmɪk ˈθɪəri/
noun
- 1. the theory that all matter is made up of tiny indivisible particles (atoms). According to the modern version, the atoms of each element are effectively identical, but differ from those of other elements, and unite to form compounds in fixed proportions.
Powered by Oxford Languages
People also ask
What is the atomic theory?
Why is atom theory important?
What was Dalton's atomic theory?
Is modern atomic theory based on old concepts?
Learn about the ancient and modern theories of matter as composed of indivisible particles called atoms. Explore the development of atomic models from Democritus to Schrödinger, and the experiments and laws that support them.
- Development of Atomic Theory
Development of atomic theory. The concept of the atom that...
- Atom
atom, the basic building block of all matter and chemistry....
- Development of Atomic Theory
- History
- Bibliography
- Further Reading
- External Links
Philosophical atomism
The idea that matter is made up of discrete units is a very old idea, appearing in many ancient cultures such as Greece and India. The word "atom" (Greek: ἄτομος; atomos), meaning "uncuttable", was coined by the Pre-Socratic Greek philosophers Leucippus and his pupil Democritus (c.460–c.370 BC). Democritus taught that atoms were infinite in number, uncreated, and eternal, and that the qualities of an object result from the kind of atoms that compose it. Democritus's atomism was refined and el...
John Dalton
Near the end of the 18th century, two laws about chemical reactions emerged without referring to the notion of an atomic theory. The first was the law of conservation of mass, closely associated with the work of Antoine Lavoisier, which states that the total mass in a chemical reaction remains constant (that is, the reactants have the same mass as the products). The second was the law of definite proportions. First established by the French chemist Joseph Proustin 1797 this law states that if...
Avogadro
The flaw in Dalton's theory was corrected in principle in 1811 by Amedeo Avogadro. Avogadro had proposed that equal volumes of any two gases, at equal temperature and pressure, contain equal numbers of molecules (in other words, the mass of a gas's particles does not affect the volume that it occupies). Avogadro's lawallowed him to deduce the diatomic nature of numerous gases by studying the volumes at which they reacted. For instance: since two liters of hydrogen will react with just one lit...
Andrew G. van Melsen (1960) [First published 1952]. From Atomos to Atom: The History of the Concept Atom. Translated by Henry J. Koren. Dover Publications. ISBN 0-486-49584-1.J. P. Millington (1906). John Dalton. J. M. Dent & Co. (London); E. P. Dutton & Co. (New York).Jaume Navarro (2012). A History of the Electron: J. J. and G. P. Thomson. Cambridge University Press. ISBN 978-1-107-00522-8.Alan J. Rocke (1984) Chemical Atomism in the Nineteenth Century: From Dalton to Cannizzaro, Ohio State University Press, Columbus (open access full text at http://digital.case.edu/islandora/object/...Learn about the first complete attempt to describe all matter in terms of atoms and their properties. Explore the postulates of Dalton's theory, the laws it was based on, and the modifications it needed.
- It is also helpful to think about how science is always evolving-we are always learning new things and modifying existing theories to take into acc...
- Actually, it is. Atoms are made up of protons, neutrons, and electrons. However, if you remove any of these particles the atom will have different...
- Sodium and chlorine are toxic/explosive because they are unstable and therefore very reactive. If you look at the electrons in the shells, they wan...
- We say that an atom can't be cut in half, not because it can't actually be split (aka nuclear fission - reactor, bomb) but rather because the resul...
- To do this would require nuclear fusion (combining smaller atomic nuclei to form a larger one), a process which is not yet quite possible in the la...
- A peer reviewed journal, ERIC, published "A Historical Note on the Conservation of Mass." This states in their abstract that this is not entirely t...
- Well there are several parts to Dalton's theory. His only theory is the atomic theory and today we know that atoms can be destroyed by nuclear reac...
- Many of Dalton's original postulates of an atomic theory have had to be modified in the light of later discoveries. As far as chemical reactions go...
- in summary: element - a basic substance that can't be simplified (hydrogen, oxygen, gold, etc...) atom - the smallest amount of an element molecule...
- You cannot add protons and neutrons because they are in the center of an atom and held tighly by the strong nuclear force. However, you can add ele...
Aug 26, 2020 · The modern atomic theory, proposed about 1803 by the English chemist John Dalton (Figure 1.5.4 ), is a fundamental concept that states that all elements are composed of atoms. Previously, an atom was defined as the smallest part of an element that maintains the identity of that element.
Dalton's Atomic Theory. The modern atomic theory, proposed about 1803 by the English chemist John Dalton (Figure \(\PageIndex{4}\)), is a fundamental concept that states that all elements are composed of atoms. Previously, an atom was defined as the smallest part of an element that maintains the identity of that element.
