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Nuclear Energy Science Tracer Bullet (Library of Congress)
Nuclear Power (Wolfram Alpha)
These are organized by a classification scheme developed exclusively for Cosma. More…
CODATA Internationally recommended values of the Fundamental Physical Constants, Atomic and Nuclear (NIST Reference on Constants, Units and Uncertainty)
Radiation, Radioactivity & Radiobiology (Martindale’s Reference Desk)
atom : the smallest particle of an element that can exist either alone or in combination — Webster
Atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element. Every solid, liquid, gas, and plasma is composed of neutral or ionized atoms. Atoms are extremely small; typical sizes are around 100 picometers (a ten-billionth of a meter, in the short scale).
Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and typically a similar number of neutrons. Protons and neutrons are called nucleons. More than 99.94% of an atom’s mass is in the nucleus. The protons have a positive electric charge, the electrons have a negative electric charge, and the neutrons have no electric charge. If the number of protons and electrons are equal, that atom is electrically neutral. If an atom has more or fewer electrons than protons, then it has an overall negative or positive charge, respectively, and it is called an ion.
The electrons of an atom are attracted to the protons in an atomic nucleus by this electromagnetic force. The protons and neutrons in the nucleus are attracted to each other by a different force, the nuclear force, which is usually stronger than the electromagnetic force repelling the positively charged protons from one another. Under certain circumstances, the repelling electromagnetic force becomes stronger than the nuclear force, and nucleons can be ejected from the nucleus, leaving behind a different element: nuclear decay resulting in nuclear transmutation.
The number of protons in the nucleus defines to what chemical element the atom belongs: for example, all copper atoms contain 29 protons. The number of neutrons defines the isotope of the element. The number of electrons influences the magnetic properties of an atom. Atoms can attach to one or more other atoms by chemical bonds to form chemical compounds such as molecules. The ability of atoms to associate and dissociate is responsible for most of the physical changes observed in nature and is the subject of the discipline of chemistry. — Wikipedia
Atomic Physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. It is primarily concerned with the arrangement of electrons around the nucleus and the processes by which these arrangements change.
The term atomic physics can be associated with nuclear power and nuclear weapons, due to the synonymous use of atomic and nuclear in standard English. Physicists distinguish between atomic physics — which deals with the atom as a system consisting of a nucleus and electrons — and nuclear physics, which considers atomic nuclei alone. — Wikipedia
Nuclear physics is the field of physics that studies atomic nuclei and their constituents and interactions. Other forms of nuclear matter are also studied. Nuclear physics should not be confused with atomic physics, which studies the atom as a whole, including its electrons. — Wikipedia
Phys.org - latest science and technology news stories Phys.org internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine.
A bridge to the quantum world
on October 22, 2018 at 2:00 pm
Monika Aidelsburger uses a special type of optical lattice to simulate quantum many-body phenomena that are otherwise inaccessible to experimental exploration. She has now been awarded an ERC Starting Grant to pursue this work. […]
One more reason to love the striped bass:...
on October 22, 2018 at 12:29 pm
It's hard to think of a fish with a higher across-the-board value than the striped bass—or rockfish, as it's known in the Chesapeake Bay region. […]
Japanese Nobel chemistry laureate Shimomura dies...
on October 22, 2018 at 7:29 am
Japanese-born Marine biologist Osamu Shimomura, who won the Nobel Prize in chemistry, has died. He was 90. […]
Breakthrough in accessing the tiny magnet within...
on October 18, 2018 at 6:00 pm
Researchers at the Center for Quantum Nanoscience (QNS) within the Institute for Basic Science (IBS) in South Korea have made a major scientific breakthrough by detecting the nuclear magnetism, or "nuclear spin" of a single atom. In an international collaboration with IBM Research, the University of Oxford and the International Iberian Nanotechnology Laboratory, QNS scientists used advanced and novel techniques to measure the nuclear spin of individual atoms on surfaces for the first time. […]
Simulating nuclear safety
on October 17, 2018 at 12:36 pm
Commercial operation of the CHASNUPP-1 996 megawatt intermediate type pressurised water reactor began in May 2000 in Pakistan. It is a conventional two-loop PWR and is run by the Pakistan Atomic Energy Commission. Now, scientists Khurram Mehboob and Mohammad Aljohani of the Department of Nuclear Engineering at King Abdul Aziz University in Saudi Arabia have carried out simulations of the activity of the unit using MATLAB to probe the risks associated with a putative coolant leak that might see […]