atom

(redirected from Atoms)
Also found in: Dictionary, Thesaurus, Acronyms, Encyclopedia.

atom

 [at´om]
the smallest particle of an element that has all the properties of the element. adj., adj atom´ic.ƒThere are two main parts of an atom: the nucleus and the electron cloud. The nucleus is made up of protons, which carry a positive electrical charge, and (except in hydrogen) neutrons, which contain one proton and one electron and carry no electrical charge. The electron cloud is made up of particles called electrons, which carry a negative electrical charge and move in orbits or “shells” around the nucleus. Different atoms have different numbers of protons, neutrons, and electrons in their makeup.

In a chemical change, atoms do not break up but act as individual units. The chemical behavior of an atom is controlled by the number and spatial arrangement of electrons in orbit around the nucleus. The atoms of radioactive elements are very unstable and are capable of emitting nuclear particles in a stream or “ray;” these particles are called radiations.

The atomic number of an element is the number of free protons (those not in neutrons) in the nucleus; it is equal to the net positive charge of the nucleus. The atomic weight is the weight of an atom of a substance as compared with the weight of an atom of carbon-12, which is taken as 12.

at·om

(at'ŏm),
Formerly considered the ultimate particle of an element, believed to be as indivisible as its name indicates. Discovery of radioactivity demonstrated the existence of subatomic particles, notably protons, neutrons, and electrons, the first two making up most of the mass of the atomic nucleus. It is now known that subatomic particles are further classified into hadrons, leptons, and quarks.
[G. atomos, indivisible, uncut]

atom

/at·om/ (at´om) the smallest particle of an element with all the properties of the element; it consists of a positively charged nucleus (made up of protons and neutrons) and negatively charged electrons, which move in orbits about the nucleus.atom´ic

atom

[at′əm]
Etymology: Gk, atmos, indivisible
1 (in chemistry and physics) the smallest division of an element that exhibits all the properties and characteristics of the element. It comprises neutrons, electrons, and protons. The number of protons in the nucleus of every atom of any given element is the same and is called its atomic number.
2
Usage notes: nontechnical,
the amount of any substance that is so small that further division is not possible. atomic, adj.

at·om

(at'ŏm)
Formerly considered the ultimate particle of an element, believed to be as indivisible as its name indicates. Discovery of radioactivity demonstrated the existence of subatomic particles, notably protons, neutrons, and electrons, the first two comprising most of the mass of the atomic nucleus. We now know that subatomic particles are further divisible into hadrons, leptons, and quarks.
[G. atomos, indivisible, uncut]

atom

the smallest particle of matter possessing the properties of an element.

atom,

n the smallest component of an element that retains the element's chemical properties. Atoms comprise molecules and are themselves divisible into electrons, neutrons, and protons.

at·om

(at'ŏm)
Formerly considered the ultimate particle of an element, discovery of radioactivity demonstrated the existence of subatomic particles, notably protons, neutrons, and electrons, the first two making up most of the mass of the atomic nucleus. Subatomic particles are now further classified into hadrons, leptons, and quarks.
[G. atomos, indivisible, uncut]

atom (at´əm),

n the smallest part of an element capable of entering into a chemical reaction.

atom

the smallest particle of an element that has all the properties of the element.
There are two main parts of an atom: the nucleus and the electron cloud. The nucleus is made up of protons, which carry a positive electrical charge, and (except in hydrogen) neutrons, which contain one proton and one electron and carry no electrical charge. The electron cloud is made up of particles called electrons, which carry a negative electrical charge and move in orbits or 'shells' around the nucleus. Different atoms have different numbers of protons, neutrons and electrons in their makeup.
The atomic number of an element is the number of free protons (those not in neutrons) in the nucleus; it is equal to the net positive charge of the nucleus.
The atomic weight is the weight of an atom of a substance as compared with the weight of an atom of carbon-12, which is taken as 12.
References in periodicals archive ?
These atoms hardly have an influence on this Rydberg electron's path.
Students count the atoms and learn that atoms need to connect together to make things.
This sharp tip can even nudge a single atom from one place to another.
ATOMIC MASS equals the number of protons plus the number of neutrons (uncharged particles) found in a single atom of an element.
Minor increases in the current flowing through the probe tip to the cobalt atom allowed Stroscio and Celotta to heat up and vibrate the lattice sites.
The slowing of atoms, for which the physics prize was given, removed a barrier to the study of these basic components of matter.
The important point, however, was that Feynman had claimed that working with atoms was entirely feasible.
Whereas AIMS was a roadblock, ATOMS was specially built to handle last-minute changes in schedules and order content with grace and elegance.
Eventually the iron will freeze, squeezing out the free carbon which will then attach itself to iron atoms to form undesirable [Fe.
Magic Wand Set: Turn into a real-life wizard that can light things up or make them explode with LED, exploding, infrared transmitter, two infrared receivers, accelerometer, flip-flop, and two battery modules, plus a magic wand frame and two AC adaptors for charging your ATOMS.
Once the researchers had achieved entanglement of the photons and atoms, they mixed the bright and dim pulses.
The experiments are performed by loading Na atoms into a "dark spot" MOT (16).