Ion
hideAn ion is an atom or molecule where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge.
Since protons are positively charged and electrons are negatively charged, if there are more electrons than protons, the atom or molecule will be negatively charged. This is called an anion (pronounced /ˈænaɪən/; an-eye-on), from the Greek ἀνά (ana), meaning 'up'.
Conversely, if there are more protons than electrons, the atom or molecule will be positively charged. This is called a cation (pronounced /ˈkætaɪən/; cat-eye-on), from the Greek κατά (kata), meaning 'down'.
An ion consisting of a single atom is called a monatomic ion. If it consists of two or more atoms, it is called a polyatomic ion. Polyatomic ions containing oxygen, such as carbonate and sulfate, are called oxyanions.
When writing the chemical formula for an ion, its charge is written as a superscript '+' or '−' following a number indicating the difference between the number of protons and the number of electrons. The number is omitted if it is equal to 1. For example, the sodium cation is written as Na+, the '+' indicating that it has one less electron than it has protons. The sulfate anion is written as SO42−, the '2−' indicating that it has two more electrons than it has protons.
If an ion contains unpaired electrons, it is called a radical ion. Just like neutral radicals, radical ions are very reactive.
For more information about Ion, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with ions
Metal Deficit in Mouse Brain Plaques Guides Direction of Human Alzheimer's Disease Research
Medicine & Health / Neuroscience
Nov 04, 2009 |
4.5 / 5 (2) |
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(PhysOrg.com) -- Minuscule plaques in the brains of mice with Alzheimer's disease contain much less metal than the brains of affected humans, according to a study conducted at the NSLS. This surprising finding ...
Hybrid molecules show promise for exploring, treating Alzheimer's
Nov 04, 2009 |
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One of the many mysteries of Alzheimer's disease is how protein-like snippets called amyloid-beta peptides, which clump together to form plaques in the brain, may cause cell death, leading to the disease's devastating symptoms ...
High-performance plasmas may make reliable, efficient fusion power a reality
Nov 02, 2009 |
4.7 / 5 (40) |
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In the quest to produce nuclear fusion energy, researchers from the DIII-D National Fusion Facility have recently confirmed long-standing theoretical predictions that performance, efficiency and reliability ...
Hunting for new zeolites
Nov 02, 2009 |
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In all the world, there are about 200 types of zeolite, a compound of silicon, aluminum and oxygen that gives civilization such things as laundry detergent, kitty litter and gasoline. But thanks to computations ...
Smart drug delivery system -- Gold nanocage covered with polymer (w/ Video)
Nov 01, 2009 |
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In campy old movies, Lucretia Borgia swans around emptying powder from her ring into wine glasses carelessly left unattended. The poison ring is usually a confection of gold filigree holding a cabochon or ...
Scientists Show Strontium's Swimming Skills
Oct 27, 2009 |
3.7 / 5 (3) |
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(PhysOrg.com) -- Recently, a trio from Pacific Northwest National Laboratory and Louisiana Tech University showed that strontium ions congregate on water's surface. Their computer simulation and careful calculations ...
A new understanding of why seizures occur with alcohol withdrawal
Medicine & Health / Neuroscience
Oct 17, 2009 |
4.7 / 5 (3) |
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Epileptic seizures are the most dramatic and prominent aspect of the "alcohol withdrawal syndrome" that occurs when a person abruptly stops a long-term or chronic drinking habit. Researchers have shown that the flow of calcium ...
Brain power goes green
Medicine & Health / Neuroscience
Oct 14, 2009 |
3 / 5 (2) |
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Our brains, it turns out, are eco-friendly. A study published in Science and reviewed by F1000 Biology members Venkatesh Murthy and Jakob Sorensen reveals that our brains have the amazing ability to be energy efficient.
Improved redox flow batteries for electric cars
Oct 13, 2009 |
4.6 / 5 (20) |
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A new type of redox flow battery presents a huge advantage for electric cars. If the rechargeable batteries are low, the discharged electrolyte fluid can simply be exchanged at the gas station for recharged ...
Radiation-Hardened Microelectronics Could Reduce Spacecraft Weight
Sep 28, 2009 |
4.3 / 5 (3) |
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(PhysOrg.com) -- Space environments can deliver a beating to spacecraft electronics. For decades, satellites and other spacecraft have used bulky and expensive shielding to protect vital microelectronics -- ...
New technology cleans up Visalia Superfund 100 years ahead of schedule
Sep 21, 2009 |
5 / 5 (2) |
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Lawrence Livermore National Laboratory's technology was instrumental in cleaning up Southern California Edison's Visalia Pole Yard, which is scheduled to be taken off the Environmental Protection Agency's Superfund list this ...
Salt and Paper Battery May One Day Replace Lithium Batteries
Sep 15, 2009 |
4.5 / 5 (17) |
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(PhysOrg.com) -- Salt and paper battery can be used in many low-power devices, such as medical implants, RFID tags, wireless sensors and smart cards. This battery uses a thin-film which makes it an attractive ...
New study explains some mysteries of neonatal seizures
Medicine & Health / Neuroscience
Sep 09, 2009 |
not rated yet |
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A study led by MassGeneral Hospital for Children (MGHfC) investigators is providing new insight into the mechanism of neonatal seizures, which have features very different from seizures in older children and adults. In their ...
Hot and Cold Moves of Cyanide and Water
Sep 08, 2009 |
not rated yet |
1
(PhysOrg.com) -- Scientists have long known that molecules dance about as the temperature rises, but now researchers know the exact steps that water takes with a certain molecule. Results with small, electrically ...
Hot and cold moves of cyanide and water
Sep 03, 2009 |
4.7 / 5 (3) |
1
Scientists have long known that molecules dance about as the temperature rises, but now researchers know the exact steps that water takes with a certain molecule. Results with small, electrically charged cyanide ...
