3 days ago · 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 …

Nov 27, 2025 · 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 …

Dec 9, 2025 · Chemical bonding - Atomic Structure, Intermolecular Forces, Covalent Bonds: To understand bond formation, it is necessary to know the general features of the electronic …

Nov 29, 2025 · The atomic hypothesis is usually credited to the Greek philosopher Democritus, who considered all matter to be composed of atoms of the four elements—earth, air, fire, and …

Nov 14, 2025 · Democritus developed his atomic philosophy as a middle ground between two opposing Greek theories about reality and the illusion of change. He argued that matter was …

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.

Most of the atom’s volume consists of a cloud of electrons that have very small mass and negative charge. The electron cloud is bound to the nucleus by the attraction of opposite …

5 days ago · By far the richest clues about the structure of the atom came from spectral line series. Mounting a particularly fine prism on a telescope, German physicist and optician …

The modern atomic theory, which has undergone continuous refinement, began to flourish at the beginning of the 19th century with the work of the English chemist John Dalton.

Dec 9, 2025 · He proposed that elements are composed of indestructible atoms, that each atom of an element is identical, that atoms of different elements differ in terms of mass, and that …