News tagged with electrons
Related topics: atoms , physical review letters , graphene , magnetic field , quantum computing
The electron is a subatomic particle that carries a negative electric charge. It has no known substructure and is believed to be a point particle. An electron has a mass that is approximately 1836 times less than that of the proton. The intrinsic angular momentum (spin) of the electron is a half integer value of 1/2, which means that it is a fermion. The anti-particle of the electron is called the positron, which is identical to electron except that it carries electrical and other charges of the opposite sign. In collisions electrons and positrons annihilate, producing a pair (or more) of gamma ray photons. Electrons participate in gravitational, electromagnetic and weak interactions.
The concept of an indivisible amount of electric charge was theorized to explain the chemical properties of atoms, beginning in 1838 by British natural philosopher Richard Laming; the name electron was introduced for this charge in 1894 by Irish physicist George Johnstone Stoney. The electron was identified as a particle in 1897 by J. J. Thomson and his team of British physicists. Electrons are identical particles that belong to the first generation of the lepton particle family. Electrons have quantum mechanical properties of both a particle and a wave, so they can collide with other particles and be diffracted like light. Each electron occupies a quantum state that describes its random behavior upon measuring a physical parameter, such as its energy or spin orientation. Because an electron is a type of fermion, no two electrons can occupy the same quantum state; this property is known as the Pauli exclusion principle.
In many physical phenomena, such as electricity, magnetism, and thermal conductivity, electrons play an essential role. An electron generates a magnetic field while moving, and it is deflected by external magnetic fields. When an electron is accelerated, it can absorb or radiate energy in the form of photons. Electrons, together with atomic nuclei made of protons and neutrons, make up atoms. However, electrons contribute less than 0.06% to an atom's total mass. The attractive Coulomb force between an electron and a proton causes electrons to be bound into atoms. The exchange or sharing of the electrons between two or more atoms is the main cause of chemical bonding.
Electrons were created by the Big Bang, and they are lost in stellar nucleosynthesis processes. Electrons are produced by cosmic rays entering the atmosphere and are predicted to be created by Hawking radiation at the event horizon of a black hole. Radioactive isotopes can release an electron from an atomic nucleus as a result of negative beta decay. Laboratory instruments are capable of containing and observing individual electrons, while telescopes can detect electron plasma by its energy emission. Electrons have multiple applications, including welding, cathode ray tubes, electron microscopes, radiation therapy, lasers and particle accelerators.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
Age has little to do with how patients should be treated after suffering a stroke, according to new research from the University of Georgia.
Cardiology May 17, 2013 | not rated yet | 0 |
(Medical Xpress)—The endothelium, the cellular layer lining the body's blood vessels, is extremely resilient. Measuring just a few hundred nanometers in thickness, this super-tenuous structure routinely ...
Medical research May 16, 2013 | 4 / 5 (2) | 1 |
(HealthDay)—Implementation of systematic monitoring for medication adherence will allow for identification of barriers to adherence and tailoring of interventions, according to a viewpoint piece published ...
Health May 22, 2013 | not rated yet | 0
The new 13-valent pneumococcal conjugate vaccine (PCV13) appears to be as safe as the previous version used prior to 2010, the 7-valent pneumococcal conjugate vaccine (PCV7), according to a Kaiser Permanente study published ...
Medications May 22, 2013 | not rated yet | 0
Failure to use linked electronic health records may lead to biased estimates of heart attack incidence and outcome, warn researchers in a paper published in BMJ today.
Health May 21, 2013 | 5 / 5 (1) | 0
(HealthDay)—The majority of physicians remain reluctant to adopt health information technology (HIT), according to a report by Deloitte Touche Tohmatsu.
Health May 20, 2013 | not rated yet | 0
(AP)—The Obama administration says more doctors and hospitals are embracing technology as adoption of computerized medical records reaches a "tipping point" in America.
Health May 22, 2013 | not rated yet | 0
Blood thinners are the preferred treatment option to prevent heart attacks, blood clots and stroke, but they are not without risk, and not just because of their side effects. These high-risk drugs, known as anticoagulants, ...
Cardiology May 22, 2013 | not rated yet | 0