
Atom | Definition, Structure, History, Examples, Diagram, & Facts ...
Mar 28, 2026 · An atom is the smallest unit into which matter can be divided without the release of electrically charged particles. It also is the smallest unit of matter that has the characteristic …
Atomic physics | Structure, Particles & Energy | Britannica
Atomic physics, the scientific study of the structure of the atom, its energy states, and its interactions with other particles and with electric and magnetic fields. Atomic physics has proved to be a …
Atom - Development, Theory, Structure | Britannica
Mar 28, 2026 · Atom - Development, Theory, Structure: The concept of the atom that Western scientists accepted in broad outline from the 1600s until about 1900 originated with Greek philosophers in the …
Atom - Quantum Mechanics, Subatomic Particles, Electrons | Britannica
Mar 20, 2026 · Atom - Quantum Mechanics, Subatomic Particles, Electrons: Within a few short years scientists developed a consistent theory of the atom that explained its fundamental structure and its …
Covalent bond | Definition, Properties, Examples, & Facts | Britannica
Mar 25, 2026 · Covalent bond, in chemistry, the interatomic linkage that results from the sharing of an electron pair between two atoms. The binding arises from the electrostatic attraction of their nuclei …
atom - Kids | Britannica Kids | Homework Help
All atoms have the same basic parts. These are a nucleus and at least one particle called an electron. The nucleus contains protons and neutrons. Diagrams of two kinds of atoms show that each kind of …
How Scientists Discovered Atoms | Britannica
Learn about the discovery of atoms and the instruments scientists use to see these small particles.
Spectroscopy - Atomic Structure, Light, Wavelengths | Britannica
Feb 20, 2026 · Spectroscopy - Atomic Structure, Light, Wavelengths: An isolated atom can be described in terms of certain discrete states called quantum states. Each quantum state has a definite energy …
Electron | Definition, Mass, & Facts | Britannica
Mar 17, 2026 · electron, one of the three basic subatomic particles —along with protons and neutrons —that make up atoms, the basic building blocks of all matter and chemistry. The negatively charged …
Periodic table | Definition, Elements, Names, Symbols, Groups, Charges ...
Mar 13, 2026 · Periodic table, in chemistry, is an organized array of all the chemical elements in order of increasing atomic number. When the elements are thus arranged, there is a recurring pattern in …