Thus, the planetary model of the atom was discarded in favor of one that described atomic orbital zones around the nucleus where a given electron is most likely to be observed.

As far as atoms and their electron shells were concerned, not only did this yield a better overall description, i. e. the atomic orbital model, but it also provided a new theoretical basis for chemistry

An atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom.

Atomic orbitals are the basic building blocks of the atomic orbital model ( alternatively known as the electron cloud or wave mechanics model ), a modern framework for visualizing the microscopic behavior of electrons in matter.

Fundamentally, an atomic orbital is a one-electron wave function, even though most electrons do not exist in one-electron atoms, and so the one-electron view is an approximation.

Although hydrogen-like orbitals are still used as pedagogical tools, the advent of computers has made STOs preferable for atoms and diatomic molecules since combinations of STOs can replace the nodes in hydrogen-like atomic orbital.

A given ( hydrogen-like ) atomic orbital is identified by unique values of three quantum numbers: n, l, and m < sub > l </ sub >.

See Linear combination of atomic orbitals molecular orbital method.

The final atomic state thus has two holes, one in the 2s orbital and the other in the 2p orbital.

This work culminated in the solar-system-like ( but quantum-limited ) Bohr model of the atom in the same year, in which a nucleus containing an atomic number of positive charge is surrounded by an equal number of electrons in orbital shells.

In this type of bond, the outer atomic orbital of one atom has a vacancy which allows addition of one or more electrons.

More sophisticated theories are valence bond theory which includes orbital hybridization and resonance, and the linear combination of atomic orbitals molecular orbital method which includes ligand field theory.

In 1929, the linear combination of atomic orbitals molecular orbital method ( LCAO ) approximation was introduced by Sir John Lennard-Jones, who also suggested methods to derive electronic structures of molecules of F < sub > 2 </ sub > ( fluorine ) and O < sub > 2 </ sub > ( oxygen ) molecules, from basic quantum principles.

This molecular orbital theory represented a covalent bond as an orbital formed by combining the quantum mechanical Schrödinger atomic orbitals which had been hypothesized for electrons in single atoms.

If we take the simple molecular orbital description of the ground state and combine that function with the functions describing all possible excited states using unoccupied orbitals arising from the same set of atomic orbitals, we also reach the full configuration interaction wavefunction.

In the early 1950s, the first semi-empirical atomic orbital calculations were carried out.

The solution of the Schrödinger equation goes much further than the Bohr model, because it also yields the shape of the electron's wave function (" orbital ") for the various possible quantum-mechanical states, thus explaining the anisotropic character of atomic bonds.

However, other factors ( such as atomic radius, nuclear charge, number of bonding orbitals, overlap of orbital energies, and crystal form ) are involved as well.

Efficiency of atomic orbital interactions is determined from the overlap ( a measure of how well two orbitals constructively interact with one another ) between two atomic orbitals, which is significant if the atomic orbitals are close in energy.

Henry Moseley developed the concept of atomic number.

These categories surely have some objects that are " special " in a certain way, such as the empty set or the product of two topologies, yet in the definition of a category, objects are considered to be atomic, i. e., we do not know whether an object A is a set, a topology, or any other abstract concept – hence, the challenge is to define special objects without referring to the internal structure of those objects.

The concept of reversed chirality also figured prominently in the plot of James Blish's Star Trek novel Spock Must Die !, where a transporter experiment gone awry ends up creating a duplicate Spock who turns out to be a perfect mirror-image of the original all the way down to the atomic level.

Notable are the Relational and the Entity-relationship models, the atomic transaction concept and related Concurrency control techniques, Query languages and Query optimization methods, RAID, and more.

The concept of a database transaction ( or atomic transaction ) has evolved in order to enable both a well understood database system behavior in a faulty environment where crashes can happen any time, and recovery from a crash to a well understood database state.

The concept of a database transaction ( or atomic transaction ) has evolved in order to enable both a well understood database system behavior in a faulty environment where crashes can happen any time, and recovery from a crash to a well understood database state.

Moseley's outstanding contribution to the science of physics was the justification from physical laws of the previous empirical and chemical concept of the atomic number.

In addition, Moseley's methods and analyses made the huge step of placing the concept of atomic number on a firm foundation based in physics.

If Prout's hypothesis had proven accurate, then the abstract concept of mass, as we now know it, might never have evolved, since mass could always be defined in terms of amounts of the hydrogen atomic mass.

The metastability concept originates in the physics of first-order phase transitions later to acquire new meanings in the study of aggregated subatomic particles ( in atomic nuclei or in atoms ) or in molecules, macromolecules or clusters of atoms and molecules.

** 104. rutherfordium, Rf, named after Ernest Rutherford, who was responsible for the concept of the atomic nucleus ( 1968 ).

A hull material that gets stronger with pressure in the film The Core was nicknamed unobtainium, but the concept under different names can be seen in the anti-gravity material cavorite and the super-strong material scrith from Larry Niven's novel Ringworld, which requires a tensile strength on the order of the forces binding an atomic nucleus together.

The concept would use a large mass spectrometer to separate an ion beam into atomic elements for later use in making products.

The concept describes the lack of an electron at a position where one could exist in an atom or atomic lattice.

To understand the concept of a valence band, it is important to consider the atomic structure of a metal first.

EBR-II was later modified to test other reactor designs, including a fast-neutron reactor and, in 1982, the Integral Fast Reactor concept — a revolutionary design that reprocessed its own fuel, reduced its atomic waste and withstood safety tests of the same failures that triggered the Chernobyl and Three Mile Island disasters.

Initially, Tibbets was unfamiliar with even the concept of an atomic bomb, and was quoted in a 1946 article in The New Yorker saying, " I will go only so far as to say that I knew what an atom was.

The concept of a database transaction ( or atomic transaction ) has evolved in order to enable both a well understood database system behavior in a faulty environment where crashes can happen any time, and recovery from a crash to a well understood database state.

The concept of atomic transaction has been extended during the years to what has become Business transactions which actually implement types of Workflow and are not atomic.

Among other research, Oliphant worked on the artificial disintegration of the atomic nucleus and positive ions, and he designed and built complex particle accelerators, being the first to conceive the concept of the proton synchrotron.

Despite its usefulness, the concept of a partial atomic charge is somewhat arbitrary, because it depends on the method used to delimit between one atom and the next ( in reality, atoms have no clear boundaries ).

* By the turn of the twentieth century, the concept of atomic and molecular entities was generally accepted, but many questions remained, not least the size of atoms and their number in a given sample.