4 days ago · 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, 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 …

Jan 31, 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 …

Mar 13, 2026 · Chemical bonding - Visualization, Atoms, Molecules: The last opposition to the existence of atoms vanished in the early 20th century when techniques were developed that portrayed visual …

Feb 21, 2026 · Nanotechnology, the manipulation and manufacture of materials and devices on the scale of atoms or small groups of atoms. The ’nanoscale’ is typically measured in nanometers, or …

6 days ago · Ion, any atom or group of atoms that bears one or more positive or negative electrical charges. Positively charged ions are called cations; negatively charged ions, anions. Ions migrate …

Mar 13, 2026 · 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 …

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 for the same …

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 …

Feb 2, 2026 · Rutherford model, description of the structure of atoms proposed (1911) by the New Zealand-born physicist Ernest Rutherford. The model described the atom as a tiny, dense, positively …