atom
Sign in to saveAtoms are the basic particles of the chemical elements and the fundamental building blocks of matter. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium, and any atom that contains 29 protons is copper. Atoms with the same number of protons but a different number of neutrons are called isotopes of the same element.
AI overview
An atom is the smallest unit of a chemical element and the fundamental building block of all matter, consisting of a nucleus containing protons and neutrons surrounded by electrons held in place by electromagnetic forces. Atoms matter because the number of protons they contain determines what chemical element they are, and this atomic composition is what gives all materials their properties and determines how they behave and interact with one another.
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Wikidata facts
- Subclass of
- composite particle
- Part of
- molecule
- Has part
- subatomic particle
- Image
- Helium atom QM.svg
Show 4 more facts
- P910
- Category:Atoms
- P2579
- chemistry
- P1552
- mass number
- P5008
- Wikipedia:Vital articles/Level/4 (2022)
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Article
34 sectionsContents
- History of atomic theory
- Philosophy
- Dalton's law of multiple proportions
- Discovery of the electron
- Discovery of the nucleus
- Bohr model
- Discovery of protons and neutrons
- The current consensus model
- Structure
- Subatomic particles
- Nucleus
- Electron cloud
- Properties
- Nuclear properties
- Mass
- Shape and size
- Radioactive decay
- Magnetic moment
- Energy levels
- Valence and bonding behavior
- States
- Identification
- Origin and current state
- Formation
- Earth
- Rare and theoretical forms
- Superheavy elements
- Exotic matter
- See also
- Notes
- References
- Bibliography
- Further reading
- External links
Atoms are the basic particles of the chemical elements and the fundamental building blocks of matter. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms. For example, any atom that contains 11 protons is sodium, and any atom that contains 29 protons is copper. Atoms with the same number of protons but a different number of neutrons are called isotopes of the same element.
Atoms are extremely small, typically around 100 picometers across. A human hair is about a million carbon atoms wide. Atoms are smaller than the shortest wavelength of visible light, which means humans cannot see atoms with conventional microscopes. They are so small that accurately predicting their behavior using classical physics is not possible due to quantum effects.