Reference Terms
from Wikipedia, the free encyclopedia
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.
Related Stories
1
2
Matter & Energy News
April 8, 2026
Apr. 6, 2026 Quantum circuits are supposed to gain power as they grow longer, but noise changes the picture. A new study finds that earlier steps in these circuits gradually lose their impact, with only the final layers really mattering. As a result, deep ...
Apr. 4, 2026 Scientists have taken a major step toward futuristic energy tech by building a working prototype of a quantum battery—one that can charge, store, and release energy using the strange rules of quantum physics instead of chemistry. This tiny, ...
Apr. 4, 2026 A new breakthrough is transforming MXenes—ultra-thin, high-tech materials—into something far more powerful and precise. Researchers have developed a cleaner, more controlled way to build these materials using molten salts and iodine, eliminating ...
Apr. 2, 2026 Fusion scientists have solved a long-standing mystery inside tokamaks, the donut-shaped machines designed to harness fusion energy. For years, experiments showed that escaping plasma particles hit one side of the exhaust system far more than the ...
Mar. 31, 2026 Scientists have transformed a groundbreaking 2D nanomaterial called MXene into an even more powerful 1D form—tiny scroll-like tubes that are incredibly thin yet highly conductive. By rolling flat ...
Mar. 31, 2026 A new shape-shifting material can change both its texture and color in seconds, inspired by the camouflage abilities of octopuses. By precisely controlling how a polymer swells with water, ...
Mar. 31, 2026 Scientists have taken lasers beyond light and into the realm of sound, creating a breakthrough “phonon laser” that manipulates tiny vibrations at the quantum level. By dramatically reducing noise ...
Mar. 31, 2026 Perovskite crystals can dramatically and reversibly change shape when hit with light, a behavior not seen in conventional semiconductors. This effect, called photostriction, can be finely tuned depending on the light’s intensity and color. ...
Mar. 29, 2026 A new holographic storage technique uses light in three dimensions to dramatically increase how much data can be stored. It encodes information throughout a material using amplitude, phase, and ...
Mar. 28, 2026 A new solar breakthrough may overcome a long-standing efficiency barrier. Researchers used a “spin-flip” metal complex to capture and multiply energy from sunlight through singlet fission. The result reached about 130% efficiency, meaning more ...
Mar. 28, 2026 Scientists have created a new kind of carbon material that could make carbon capture much cheaper and more efficient. By carefully controlling how nitrogen atoms are arranged, they found certain structures capture CO2 better and release it using far ...
Mar. 27, 2026 Researchers have uncovered a new way to generate exotic oscillation states in tiny magnetic structures—using only minimal energy. By exciting magnetic waves, they triggered a delicate motion that produced a rich spectrum of signals never seen ...
Latest Headlines
updated 12:56 pm ET
Apr. 8, 2026 A bizarre, record-breaking neutrino detected in 2023 may have originated from an exploding primordial black hole—a relic from the early universe. ...
Apr. 7, 2026 Scientists have zoomed in on how phosphoric acid moves electrical charges so efficiently in both biology and technology. By freezing a key molecular pair to extremely low temperatures, they found it ...
Apr. 6, 2026 Scientists have taken a major step toward probing one of physics’ biggest mysteries—how gravity and quantum mechanics fit together—by creating the first unified way to detect tiny “ripples” ...
Apr. 3, 2026 Saturn’s magnetic field isn’t the smooth, symmetrical shield scientists see around Earth. Instead, it’s noticeably skewed, and researchers now think they understand why. By analyzing years of ...
Mar. 30, 2026 Scientists at the University of Waterloo have uncovered a bold new way to explain how the universe began—one that could reshape our understanding of the Big Bang. Instead of relying on ...
Mar. 30, 2026 Scientists have discovered something that seems almost impossible: under the right conditions, ordinary liquids can snap apart like solid objects. In experiments, researchers found that when certain ...
Mar. 29, 2026 Scientists have finally found a hidden “critical point” in supercooled water that explains why it behaves so strangely. At this point, two different liquid forms of water merge, triggering ...
Mar. 29, 2026 A team of physicists set out to test some of the most exciting claims in quantum computing—and found a very different story. Instead of confirming breakthroughs, their careful replication studies ...
Mar. 25, 2026 A star you can see with the naked eye has kept astronomers guessing for decades with its unusually powerful X-rays. Now, thanks to highly precise observations from Japan’s XRISM space telescope, ...
Mar. 24, 2026 Researchers have visualized atoms in motion just before a radiation-driven decay process occurs, revealing a surprisingly dynamic scene. Instead of remaining fixed, the atoms roam and rearrange, ...