DNA-like material could bring even smaller transistors
Computer chips use billions of tiny switches, called transistors, to process information. The more transistors on a chip, the faster the computer.
Feb 10, 2020
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Electronics & Semiconductors
Computer chips use billions of tiny switches, called transistors, to process information. The more transistors on a chip, the faster the computer.
Feb 10, 2020
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123
Engineering
2-D semiconductors could have very useful applications, particularly as channel materials for low-power transistors. These materials display very high mobility at extreme thicknesses, which makes them particularly promising ...
Energy & Green Tech
A new method could enable researchers to fabricate more efficient and longer lasting perovskite solar cells, LEDs and photodetectors. By growing thin perovskite films on substrates with different compositions, engineers at ...
Jan 9, 2020
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Energy & Green Tech
Japan's economy and industry ministry proposed on Monday the gradual release or evaporation of massive amounts of treated but still radioactive water being stored at the tsunami-wrecked Fukushima nuclear plant.
Dec 23, 2019
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Energy & Green Tech
One of four Swiss nuclear power stations was permanently disconnected Friday after 47 years of service, marking a first in Switzerland, as the country begins to gradually phase out atomic energy.
Dec 20, 2019
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Energy & Green Tech
Europe's oldest functioning nuclear reactor, at Switzerland's Beznau plant, will turn 50 next week—a lifespan deemed dangerously long by environmentalists who are demanding that it be shut down immediately.
Dec 5, 2019
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Electronics & Semiconductors
Slightly bending semiconductors made of organic materials can roughly double the speed of electricity flowing through them and could benefit next-generation electronics such as sensors and solar cells, according to Rutgers-led ...
Dec 3, 2019
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Machine learning & AI
Time to stock up on tissues.
Nov 13, 2019
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Engineering
A team lead by Professor Simon Brown at the University of Canterbury (UC) has developed computer chips with brain-like functionality, that could significantly reduce global carbon emissions from computing.
Nov 6, 2019
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Energy & Green Tech
How do solar panels work? – Nathan, age 5, Melbourne, Australia.
Nov 6, 2019
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The atom is a basic unit of matter consisting of a dense, central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons (except in the case of hydrogen-1, which is the only stable nuclide with no neutron). The electrons of an atom are bound to the nucleus by the electromagnetic force. Likewise, a group of atoms can remain bound to each other, forming a molecule. An atom containing an equal number of protons and electrons is electrically neutral, otherwise it has a positive or negative charge and is an ion. An atom is classified according to the number of protons and neutrons in its nucleus: the number of protons determines the chemical element, and the number of neutrons determine the isotope of the element.
The name atom comes from the Greek ἄτομος/átomos, α-τεμνω, which means uncuttable, something that cannot be divided further. The concept of an atom as an indivisible component of matter was first proposed by early Indian and Greek philosophers. In the 17th and 18th centuries, chemists provided a physical basis for this idea by showing that certain substances could not be further broken down by chemical methods. During the late 19th and early 20th centuries, physicists discovered subatomic components and structure inside the atom, thereby demonstrating that the 'atom' was divisible. The principles of quantum mechanics were used to successfully model the atom.
Relative to everyday experience, atoms are minuscule objects with proportionately tiny masses. Atoms can only be observed individually using special instruments such as the scanning tunneling microscope. Over 99.9% of an atom's mass is concentrated in the nucleus, with protons and neutrons having roughly equal mass. Each element has at least one isotope with unstable nuclei that can undergo radioactive decay. This can result in a transmutation that changes the number of protons or neutrons in a nucleus. Electrons that are bound to atoms possess a set of stable energy levels, or orbitals, and can undergo transitions between them by absorbing or emitting photons that match the energy differences between the levels. The electrons determine the chemical properties of an element, and strongly influence an atom's magnetic properties.
This text uses material from Wikipedia, licensed under CC BY-SA