
Atom | Definition, Structure, History, Examples, Diagram, & Facts ...
5 days ago · However, atoms are made up of three types of subatomic particles: the heavy protons and neutrons that make up the nucleus (the central part of the atom), and the much …
Atom - Development, Theory, Structure | Britannica
5 days ago · Democritus believed that atoms were uniform, solid, hard, incompressible, and indestructible and that they moved in infinite numbers through empty space until stopped. …
Atomic physics | Structure, Particles & Energy | Britannica
It attempts to describe and account for the properties of molecules and atoms and their constituents— electrons, protons, neutrons, and other more esoteric particles such as quarks …
atom - Kids | Britannica Kids | Homework Help
The tiny particles called atoms are the basic building blocks of all matter. Atoms can be combined with other atoms to form molecules, but they cannot be divided into smaller parts by ordinary …
atom - Students | Britannica Kids | Homework Help
Atoms are made up of three basic types of particle: protons, neutrons, and electrons. These particles (as well as other particles smaller than atoms) are known as subatomic particles.
Atomism | Definition, Philosophy, History, & Facts | Britannica
Atomism in the strict sense is characterized by three points: the atoms are absolutely indivisible, qualitatively identical (i.e., distinct only in shape, size, and motion), and combinable with each …
Chemical bonding - Covalent, Molecules, Atoms | Britannica
Sep 5, 2025 · Chemical bonding - Covalent, Molecules, Atoms: When none of the elements in a compound is a metal, no atoms in the compound have an ionization energy low enough for …
John Dalton - Atomic Theory, Chemistry, Physics | Britannica
Oct 21, 2025 · Dalton claimed that atoms of different elements vary in size and mass, and indeed this claim is the cardinal feature of his atomic theory.
Atom - Quantum Mechanics, Subatomic Particles, Electrons
Sep 7, 2025 · The different energy levels of atoms are identified with the simple vibrational modes of the wave equation. The equation is solved to find these modes, and then the energy of an …
Democritus | Biography & Facts | Britannica
Oct 2, 2025 · Democritus devoted considerable attention to perception and knowledge. He asserted, for example, that sensations are changes produced in the soul by atoms emitted …