
Atom | Definition, Structure, History, Examples, Diagram, & Facts ...
Jan 9, 2026 · Chemical elements are made up of only one type of atom—gold contains only gold atoms, and neon contains only neon atoms--and they are ranked in order of their atomic number (the total …
Atom - Development, Theory, Structure | Britannica
Jan 9, 2026 · 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 and gluons.
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 means.
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
Dec 23, 2025 · Atomism is usually associated with a “ realistic ” and mechanistic view of the world. It is realistic in that atoms are not considered as subjective constructs of the mind employed for the sake …
Atom - Quantum Mechanics, Subatomic Particles, Electrons | Britannica
Jan 9, 2026 · In Heisenberg’s method, properties of atoms are described by arrays of numbers called matrices, which are combined with special rules of multiplication. Today physicists use both wave …
Periodic table | Definition, Elements, Names, Symbols, Groups, Charges ...
Dec 22, 2025 · The sizes of atoms are of importance in the determination of coordination number (that is, the number of groups attached to the central atom in a compound) and hence in the composition …
Atom - Electrons, Nucleus, Bonds | Britannica
Jan 9, 2026 · Atom - Electrons, Nucleus, Bonds: Once the way atoms are put together is understood, the question of how they interact with each other can be addressed—in particular, how they form …
Molecule | Definition, Examples, Structures, & Facts | Britannica
Jan 5, 2026 · Atoms consist of a single nucleus with a positive charge surrounded by a cloud of negatively charged electrons. When atoms approach one another closely, the electron clouds …