atomic cloud
11Atomic and molecular astrophysics — Within a few million years the light from bright stars will have boiled away this molecular cloud of gas and dust. The cloud has broken off from the Carina Nebula. Newly formed stars are visible nearby, their images reddened by blue light being… …
12Atomic radius — Diagram of a helium atom, showing the electron probability density as shades of gray. The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the nucleus to the boundary of the… …
13atomic bomb — 1. a bomb whose potency is derived from nuclear fission of atoms of fissionable material with the consequent conversion of part of their mass into energy. 2. a bomb whose explosive force comes from a chain reaction based on nuclear fission in U… …
14atomic theory — 1. Physics, Chem. any of several theories describing the structure, behavior, and other properties of the atom and its component parts. 2. Philos. atomism (def. 1). [1840 50] * * * ▪ physics ancient philosophical speculation that all things …
15atomic radius — ▪ physics half the distance between the nuclei of identical neighbouring atoms. An atom has no rigid spherical boundary, but it may be thought of as a tiny, dense positive nucleus surrounded by a diffuse negative cloud of electrons. The… …
16Atomic fountain — An atomic fountain is a cloud of atoms that are tossed upwards by lasers in the Earth s gravitational field. If visible, it would resemble the water in a fountain. While weightless in the toss, the atoms are measured to set the frequency of an… …
17atomic nucleus — noun A nucleus of an atom; consisting of protons and neutrons, surrounded by an electron cloud …
18Mushroom cloud — created by smoke billows Ascending cloud from Redoubt Vol …
19Electron cloud — is a term used, if not originally coined, by the Nobel Prize laureate and acclaimed educator Richard Feynman in The Feynman Lectures on Physics (Feynman2006 Vol 1 lect 6 pg 11) for discussing exactly what is an electron? . This intuitive model… …
20Debate over the atomic bombings of Hiroshima and Nagasaki — The Fat Man mushroom cloud resulting from the nuclear explosion over Nagasaki rises 18 km (11 mi, 60,000 ft) into the air from the hypocenter …
