Atom | Definition, Structure, History, Examples, Diagram, & Facts ...
2024年10月8日 · Atoms that have the same number of electrons in the outer shell have similar chemical properties. This article opens with a broad overview of the fundamental properties of the atom and its constituent particles and forces.
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.
Atom - Development, Theory, Structure | Britannica
2024年10月8日 · In Democritus’s philosophy, atoms existed not only for matter but also for such qualities as perception and the human soul. For example, sourness was caused by needle-shaped atoms, while the colour white was composed of smooth-surfaced atoms.
Atomic model | Definition, History, Development, Examples,
atomic model, in physics, a model used to describe the structure and makeup of an atom. Atomic models have gone through many changes over time, evolving as necessary to fit experimental data. For a more in-depth discussion of the history of …
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. The word atom comes from the Greek word atomos, meaning “indivisible.”.
Atom - Electrons, Orbitals, Energy | Britannica
2024年10月8日 · The next most-complex atom is helium, which has two protons in its nucleus and two orbiting electrons. These electrons fill the two available states in the lowest shell, producing what is called a filled shell. The next atom is lithium, with three electrons.
Atomic theory | Definition, Scientists, History, & Facts | Britannica
Atomic theory, ancient philosophical speculation that all things can be accounted for by innumerable combinations of hard, small, indivisible particles (called atoms) of various sizes but of the same basic material; or the modern scientific theory of …
Atom - Electrons, Nucleus, Bonds | Britannica
2024年10月8日 · 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 bonds to create molecules and macroscopic materials.
Molecule | Definition, Examples, Structures, & Facts | Britannica
2024年10月21日 · Molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical properties of that substance. Learn more about the properties and structures of molecules in …
Periodic table | Definition, Elements, Groups, Charges, Trends,
2 天之前 · Periodic table, in chemistry, the organized array of all the chemical elements in order of increasing atomic number. When the elements are thus arranged, there is a recurring pattern called the ‘periodic law’ in their properties, in which elements in the same column (group) have similar properties.