Atom
An atom is the basic unit of a chemical element, consisting of a central, positively-charged nucleus which is surrounded by a cloud of orbiting negatively-charged electrons.
Atom:
An atom is the smallest unit into which matter can be divided without charged particles being released. It also is the smallest unit of matter with the characteristic properties of an element.
Atom Smasher remains in the Middle Eastern nation for a time, although he eventually begins to question Adam's motives. Rothstein perishes in JSA #75 while fighting against the Spectre
Spectre (comics) ...
H-Atom: Areal Velocity
Areal Velocity
Kepler's second law states that the areas swept out by a planet during a common time interval are the same. Thus the yellow areas below should all have the same area. Do they?
Understanding the Atom
The nucleus of an atom is surround by electrons that occupy shells, or orbitals of varying energy levels.
The ground state of an electron, the energy level it normally occupies, is the state of lowest energy for that electron.
Atom. The basic structure of which all matter is made. It is made up of three particles; protons and neutrons (which make up the nucleus) and electrons (which orbit the nucleus).
ATOM
The tiny building block that makes up everything.
B
BACTERIA
Living things that have only one cell and are so small they can only be seen with a microscope.
Atom- the smallest part of an element that can take part in a chemical reaction; most of the mass of the an atom is concentrated in its nucleus, which is about .000000000001 meters (.01 angstroms) across ...
atom Building block of matter, composed of positively charged protons and neutral neutrons in the nucleus, surrounded by negatively charged electrons.
atom
the fundamental unit of matter; can consist of protons, neutrons, and electrons
atomic nucleus ...
Atom - A particle consisting of a nucleus and one or more surrounding electrons ...
Atom A fundamental constituent of matter. All substances consist of atoms, usually combined chemically into molecules.
ATOM - Smallest particle of a chemical element that retains the properties of that element.
Atom
(a) The smallest component of matter that retains its chemical properties. An atom consists of a nucleus and at least one electron.
(b) The building block of matter.
Bohr atom
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Excited Atom
An atom in which an electron has moved from a lower to higher orbit.
Extinction ...
Atom
The smallest unit of matter that possesses chemical properties. All atoms have the same basic structure: a nucleus containing positively charged protons with an equal number of negatively charged electrons orbiting around it.
Atom A basic unit of matter. It is the smallest particle of an element that still has the characteristics of that element. Every atom has a positively charged central nucleus, surround by a number of negatively charged electrons.
More about atoms...
atom epoch - (n.)
Fourth epoch in the history of the Universe, lasting from about 100 sec to 106 yr, in which matter came to dominate radiation as the principal constituent of the Universe.
atomic mass unit - (n.) ...
atom, molecule, nucleus, proton, neutron, electron
scientific notation
Proxima Centauri ...
Atom
Isotope table (divided) - table of all known isotopes
Isotope table (complete)
Isotopomer
Table of nuclides
List of particles
Isotopes are nuclides having the same number of protons; compare: ...
An atom or a molecule can absorb light and undergo a transition from one quantum state to another. The oscillator strength is a dimensionless quantity to express the strength of the transition.
An atom that, because of the loss of one or more electrons, has a positive electrical charge.
J
Jovian ...
Any atom, or collection of atoms, has a property called mass, which measures how much material there is in the object. On the surface of the Earth, the gravity of the Earth pulls downwards on all masses giving the sensation of weight.
The Atom and Spectroscopy is a visual page of lecture notes emphasising how spectral lines are produced. It also discusses the Doppler effect and provides a simulation for it.
Each atom has a unique fingerprint because each can only emit or absorb certain wavelengths of energy. Thus, the fingerprint -- as seen in the location and spacing of spectral lines -- is unique for each atom.
In an atom, an electron in an incompletely filled (usually outer) shell, available for chemical bonding to form a molecule. [DC99]
Van Allen (Radiation) Belts ...
In the atom the dominant force is the electrical force between the nucleus and the electrons; this force determines the characteristic structure, or energy levels, of the atom.
Hydrogen atom energy levels (n=1,2,3...)
Lyman (n=1), Balmer (n=2), etc series of lines
Kirchoff's Laws : conditions for ...
11. An atom can remain in an excited state indefinitely. HINT
12. Emission and absorption lines correspond to the specific energy differences between orbitals in an atom. HINT ...
Inside an Atom
Light lets us peek inside the atom -- if we know how to look. According to the simple Bohr model, an atom consists of a nucleus around which electrons buzz in orbits.
Ion
an atom that has lost or gained one or more electrons and has become electrically charged as a result.
The simplest atom is the hydrogen atom, which has only one proton in its nucleus, denoted by 1H.
[2.1] THE BOHR ATOM
[2.2] DE BROGLIE & WAVE-PARTICLE DUALITY / QUANTUM STATISTICS
[2.3] WERNER HEISENBERG & MATRIX MECHANICS ...
Stylized Lithium Atom by Halfdan
If you want to freak out most people, just mention chemistry. Chemistry is difficult for the average person to understand, so many simply shy away from it.
ION
An ion is an atom that is missing one or more electrons; ions have an electrical charge.
The center of an Atom is made up of one or more protons. It has a positive charge.
Quasar
A very distant immensely bright object.
An atom is shown with the electron in the lowest (ground) energy level. Light of just the right wavelength is absorbed by the electron, causing it to go into a higher energy level.
pair production An absorption process for X-ray and gamma ray radiation in which the incident photon is annihilated in the vicinity of the nucleus of the absorbing atom, with subsequent production of an electron and positron pair.
aldehydes (NASA Thesaurus) Carbonyl groups to which a hydrogen atom is attached; the first stage of an alcohol; - CHO.
An Angstrom is on the order of the size of an atom.
Arc Degree A unit of angular measure in which there are 360 arc degrees in a full circle.
Arc Second Abbreviated arcsec.
If the particle is a neutral hydrogen atom, it is acted upon only by the solar gravitation (the effect of a magnetic field upon a possible atomic magnetic moment being negligible).
In these detectors a neutrino would convert a chlorine atom into one of argon. The fluid would periodically be purged with helium gas which would remove the argon. The helium would then be cooled to separate out the argon.
The solar neutrino experiment of astronomer Ray Davis is based upon the fact that neutrinos can interact with a chlorine atom to become an argon atom.
See also: Fireball, Meteor, Meteoroid, Micrometeorite Meteoroid A solid object moving in interplanetary space, of a size considerably smaller than a asteroid and considerably larger than an atom or molecule.
To understand what happens next we have to know a bit about the structure of an atom.
It's a band of radio frequencies sandwiched between emission from neutral hydrogen - 1,420 MHz (a wavelength of 21cm) - and emission from molecules of hydroxyl (1,666MHz, 18cm wavelength), which is composed of one atom of hydrogen, ...
6 eV per atom is readily available. This may come from OB stars, from hot evolved stars (as in planetary nebulae), or from interstellar shocks (as in supernova remnants).
During 1948 the Russian-American physicist George Gamow modified Lemaître's theory of the primeval atom into the big bang theory of the origin of the universe.
Charge: An atom becomes an ion when it gains or loses an electron (a negatively charged particle). When an atom loses an electron, it becomes positively charged because the negative electron balanced out a positive proton.
For each silicon atom in the cosmic mixture, there are 24 oxygen atoms. Thus after a sufficient amount of oxygen has combined with all the available silicon to form rocks, an excess of oxygen remains that can combine with hydrogen to make water.
The ionization of an atom in a plasma has two effects. First, the heat capacity of the plasma is larger within than outside the temperature range over which ionization occurs.
Georges Lemaitre proposed what became known as the Big Bang theory of the origin of the universe, he called it his "hypothesis of the primeval atom".
When light (or other energy) is absorbed by the atom, an electron jumps from a low energy orbital to a higher energy orbital. When an electron returns to a less energetic orbital, light (or other electromagnetic radiation) is generated.
Definition: spectral line: Light given off at a specific frequency by an atom or molecule.
Spectral line: Light given off at a specific frequency by an atom or molecule. Every different type of atom or molecule gives off light at its own unique set of frequencies.
Light given off at a specific frequency by an atom or molecule. Every different type of atom or molecule gives off light at its own unique set of frequencies; thus, ...
It begins when a normal carbon atom (C-12, with 6 protons and 6 neutrons) picks up a proton to make radioactive nitrogen-13, ...
Nuclear fission is a reaction in which an atom's nucleus is broken apart, releasing a tremendous amount of energy. Nuclear fission is used in many power plants on Earth (and is used in atomic weapons).
Carbon dioxide: A compound formed by combining one carbon atom with two oxygen atoms, making the molecule CO2. Carbon dioxide is an important part of the atmospheres of Venus and Mars. Carbon dioxide gas condenses to a solid below -78o C.
 See also: Light, Energy, Electron, Time, Earth
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