(physics). The science concerned with the structure of the atom, the characteristics of the elementary particles of which the atom is composed, and the processes involved in the interactions of radiant energy with matter.
http://encyclopedia2.thefreedictionary.com/Atomic+physics
In the second decade of the 20th century it was established that the atom consisted of a nucleus and electrons bound together by electrical forces. In the first phase of its development, atomic physics also included problems associated with the structure of the atomic nucleus.
http://encyclopedia2.thefreedictionary.com/Atomic+physics
Part of the Nanotechnology glossary: Quantum theory is the theoretical basis of modern physics that explains the nature and behavior of matter and energy on the atomic and subatomic level. The nature and behavior of matter and energy at that level is sometimes referred to as quantum physics and quantum mechanics.
http://whatis.techtarget.com/definition/quantum-theory
Modern atomic physics. The basic branches of modern atomic physics are the theory of the atom, atomic (optical) spectroscopy, X-ray spectroscopy, radio spectroscopy (which also investigates the rotational levels of molecules), and the physics of atomic and ion collisions.
http://encyclopedia2.thefreedictionary.com/Atomic+physics
The protons and the neutrons make up the center of the atom called the nucleus and the electrons fly around above the nucleus in a small cloud. The electrons carry a negative charge and the protons carry a positive charge. In a normal (neutral) atom the number of protons and the number of electrons are equal. Often, but not always, the number of neutrons is the same, too.
http://www.universetoday.com/56347/atom-definition/
They must group to form the protons, electron, and neutrons normally found in a single atom of an element. They have only been found as a result of a particle collider and in theory. An atom itself is made up of three tiny kinds of particles called subatomic particles: protons, neutrons, and electrons.
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The two major interpretations of quantum theory's implications for the nature of reality are the Copenhagen interpretation and the many-worlds theory.
http://whatis.techtarget.com/definition/quantum-theory
by Jerry Coffey on February 17, 2010. The atom definition is: A unit of matter, the smallest unit of an element, having all the characteristics of that element and consisting of a dense, central, positively charged nucleus surrounded by a system of electrons.
http://www.universetoday.com/56347/atom-definition/
Quantum theory and Einstein's theory of relativity form the basis for modern physics. The principles of quantum physics are being applied in an increasing number of areas, including quantum optics, quantum chemistry, quantum computing, and quantum cryptography. See Brian Greene's introduction to quantum theory on Nova:
http://whatis.techtarget.com/definition/quantum-theory
Atomic physics. The study of the structure of the atom, its dynamical properties, including energy states, and its interactions with particles and fields. These are almost completely determined by the laws of quantum mechanics, with very refined corrections required by quantum electrodynamics.
http://encyclopedia2.thefreedictionary.com/Atomic+physics
define the atom in physics
In physics, the atom is a unit of matter, the smallest unit of an element, having all the characteristics of that element and consisting of a dense, central, positively charged nucleus surrounded by a system of electrons. The atom is a unit of matter, the smallest unit of an element, having all the characteristics of that element and consisting of a dense, central, positively charged nucleus surrounded by a system of electrons.