Reference Terms
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Atom
In chemistry and physics, an atom is the smallest particle of a chemical element that retains its chemical properties. An atom consists of a dense nucleus of positively-charged protons and electrically-neutral neutrons, surrounded by a much larger electron cloud consisting of negatively-charged electrons. An atom is electrically neutral if it has the same number of protons as electrons. The number of protons in an atom defines the chemical element to which it belongs, while the number of neutrons determines the isotope of the element.
The first nuclei, including most of the helium and all of the deuterium in the universe, were theoretically created during big bang nucleosynthesis, about 3 minutes after the big bang. The first atoms were theoretically created 380,000 years after the big bang, an epoch called recombination, when the universe cooled to allow electrons to become attached to nuclei. Since then, atoms have been combined in stars through the process of nuclear fusion to generate atoms up to Iron.
A human hair is about 1 million carbon atoms wide.
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Matter & Energy News
September 20, 2026
Sep. 20, 2026 Scientists have developed ultra-bright nanoparticles that can detect tiny amounts of chemicals and distinguish between molecules that look almost identical. The technology could one day provide a cheaper way to catch dangerous drug impurities or ...
Sep. 19, 2026 A deep-sea microbe uses an exceptionally heat-resistant enzyme to turn atmospheric nitrogen into ammonia at temperatures that would destroy most proteins. Its unusual structure and a newly observed reaction state may reveal an ancient, shared ...
Sep. 19, 2026 Complex systems may work better when their parts are not perfectly alike. Northwestern physicists found that carefully balanced variation, or “disorder,” can make networks such as power grids, ecosystems, neurons, and materials more stable. Even ...
Sep. 18, 2026 Scientists are looking to diatoms, sea sponges, and plants for a cleaner way to recover rare earth elements and other valuable minerals hidden inside coal ash, red mud, and mine tailings. The bio-inspired approach could turn massive industrial waste ...
Sep. 18, 2026 A new Caltech device can redirect a beam of light in just 74 femtoseconds using another beam and a nanoscale silicon metasurface. The breakthrough could pave the way for dramatically faster photonic communications, computing, and sensing ...
Sep. 17, 2026 A pocket-sized, roughly $100 detector can reveal the invisible stream of cosmic particles constantly passing through Earth and even through our bodies. What began as a student physics project is now being used in major experiments, balloon missions, ...
Sep. 16, 2026 Scientists have developed a solar-powered desalination system that turns seawater into fresh water while removing nearly all of the leftover salt as a solid instead of producing harmful brine. The self-cleaning technology could also recover valuable ...
Sep. 15, 2026 A mathematical shape famous for covering a surface without ever repeating has revealed an unexpected ability to twist light into unusual chiral patterns. The discovery could lead to new ways of controlling light, polarization, and advanced optical ...
Sep. 13, 2026 Scientists are combining an electron microscope with a quantum computer to squeeze far more information from each electron. The approach could reveal faint details with fewer electrons, helping protect fragile samples that conventional microscopy ...
Sep. 13, 2026 Researchers have experimentally demonstrated the optical Magnus effect for the first time, revealing that a tightly focused laser interacts most strongly with an atom slightly away from the beam’s center. The unexpected shift is similar to the ...
Sep. 12, 2026 Researchers at Harvard have demonstrated a way to protect quantum information using microscopic sound waves. By continuously surrounding a diamond-based qubit with mechanical vibrations, they extended its coherence time by roughly threefold. The ...
Sep. 11, 2026 Scientists have created an ultra-small nanolaser that could eventually allow microchips to transmit information with light instead of electricity, potentially making computers faster while cutting energy use roughly in half. Thousands of the lasers ...
Latest Headlines
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Sep. 20, 2026 A decade-long NIST experiment has produced a new measurement of the universal gravitational constant that differs unexpectedly from another leading ...
Sep. 20, 2026 Physicists have detected strong evidence that heavy, fleeting Z bosons can become quantum entangled during Higgs boson decays at CERN’s Large ...
Sep. 18, 2026 Scientists have found a new way to create a controlled beam of muonium, an exotic atom containing a heavier cousin of the electron. The advance could allow researchers to test for the first time ...
Sep. 14, 2026 A foundational chemistry concept found in textbooks for almost 100 years may have been taught incorrectly. Researchers say the inductive effect in neutral molecules appears to extend only across one ...
Sep. 13, 2026 A massive worldwide survey of physicists has revealed surprisingly little agreement about some of the universe’s biggest mysteries. No majority backed the standard cosmological model, a leading ...
Sep. 12, 2026 Physicists at CERN have found a new way to peer deep inside atomic nuclei and distinguish between two competing explanations for how gluons behave. Using the ALICE experiment at the Large Hadron ...
Sep. 11, 2026 Unconventional quantum theories may imply that time itself has a tiny fundamental uncertainty, placing an ultimate limit on how precisely any clock could measure it. The effect is far beyond current ...
Sep. 10, 2026 Researchers have created a foam-based material that produces intense whiteness and water repellency without titanium dioxide pigments or PFAS chemicals. Inspired by natural structures in snow, ...
Sep. 9, 2026 Scientists discovered that charged water droplets can damage protective coatings by releasing tiny electrical discharges when they hit a surface. The hidden effect could help explain weathering and ...
Sep. 9, 2026 Scientists found that a tiny atomic structure that forms on nickel oxide during methane conversion is more effective than the metallic nickel long believed to drive the reaction. The discovery ...