ETYM Cf. French atomique.
1. Immeasurably small; SYN. atomlike, minute.
2. Of or relating to of comprising atoms.
Of atoms.

Množina: Atomic Ages

Množina: atomic bombs

Bomb deriving its explosive force from nuclear fission (see nuclear energy) as a result of a neutron chain reaction, developed in the 1940s in the US into a usable weapon.
Research began in the UK 1940 and was transferred to the US after its entry into World War II the following year. Known as the Manhattan Project, the work was carried out under the direction of the US physicist Robert Oppenheimer at Los Alamos, New Mexico. After one test explosion, two atomic bombs were dropped on the Japanese cities of Hiroshima (6 Aug 1945) and Nagasaki (9 Aug 1945); the bomb dropped on Hiroshima was as powerful as 12,700 metric tons of TNT, that on Nagaskai was equivalent to 22,000 metric tons of TNT. The USSR first detonated an atomic bomb 1949 and the UK 1952.

Singular of atomic bombs is atomic bomb.

Množina: atomic cannons

Množina: atomic clocks

A timepiece that derives its time scale from the vibration of atoms or molecules.
Timekeeping device regulated by various periodic processes occurring in atoms and molecules, such as atomic vibration or the frequency of absorbed or emitted radiation.
The first atomic clock was the ammonia clock, invented at the US National Bureau of Standards 1948. It was regulated by measuring the speed at which the nitrogen atom in an ammonia molecule vibrated back and forth. The rate of molecular vibration is not affected by temperature, pressure, or other external influences, and can be used to regulate an electronic clock.
A more accurate atomic clock is the cesium clock. Because of its internal structure, a cesium atom produces or absorbs radiation of a very precise frequency (9,192,631,770 Hz) that varies by less than one part in 10 billion. This frequency has been used to define the second, and is the basis of atomic clocks used in international timekeeping.
Hydrogen maser clocks, based on the radiation from hydrogen atoms, are the most accurate. The hydrogen maser clock at the US Naval Research Laboratory, Washington, DC, is estimated to lose one second in 1,700,000 years. Cooled hydrogen maser clocks could theoretically be accurate to within one second in 300 million years.
Atomic clocks are so accurate that minute adjustments must be made periodically to the length of the year to keep the calendar exactly synchronized with the Earth's rotation, which has a tendency to speed up or slow down. There have been 17 adjustments made since 1972. In 1992 the northern hemisphere's summer was longer than usual—by one second. An extra second was added to the world's time at precisely 23 hours, 59 minutes and 60 seconds on 30 June 1992. The adjustment was called for by the International Earth Rotation Service in Paris, which monitors the difference between Earth time and atomic time.

Množina: atomic dusts

Množina: atomic energies

Nuclear energy regarded as a source of power; SYN. atomic power, nuclear power.
Former name for nuclear energy.

Množina: atomic formulas

Množina: atomic fusions