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
Researchers analyze material with 'colossal ionic conductivity'
Jul 31, 2008 |
4.8 / 5 (46) |
5
A new material characterized at the Department of Energy's Oak Ridge National Laboratory could open a pathway toward more efficient fuel cells.
High-performance plasmas may make reliable, efficient fusion power a reality
Nov 02, 2009 |
4.7 / 5 (40) |
48
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 ...
Coming Soon: Improved Lithium Ion Batteries?
Nov 19, 2008 |
4.6 / 5 (33) |
1
(PhysOrg.com) -- Rechargeable lithium ion batteries provide portable devices that require a lot of energy, such as mobile telephones, digital cameras, and notebook computers, with power. However, their capacity, and thus ...
Oxygen Ions for Fuel Cells Get Loose at Low Temperatures
Jun 25, 2008 |
4.2 / 5 (29) |
0
Seeking to understand a new fuel cell material, a research team working at the National Institute of Standards and Technology (NIST), in collaboration with the University of Liverpool, has uncovered a novel ...
Salt Water System Could Generate Hydrogen
Mar 18, 2009 |
3.9 / 5 (31) |
18
(PhysOrg.com) -- The idea of generating hydrogen from salt water has often been claimed to work effectively. However, the systems proposed so far generally require a much greater energy input than the energy ...
Renewable Energy Made by Mixing Salt and Fresh Water
Sep 02, 2009 |
4.3 / 5 (27) |
6
(PhysOrg.com) -- When a river flows into the sea, the location is more than just a haven for water commerce. The mixing of fresh and salt water that occurs at an estuary also dissipates energy, as the different ...
Improved redox flow batteries for electric cars
Oct 13, 2009 |
4.6 / 5 (20) |
14
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 ...
Salt and Paper Battery May One Day Replace Lithium Batteries
Sep 15, 2009 |
4.5 / 5 (17) |
6
(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 ...
Wastewater produces electricity and desalinates water
Aug 06, 2009 |
4.5 / 5 (16) |
1
A process that cleans wastewater and generates electricity can also remove 90 percent of salt from brackish water or seawater, according to an international team of researchers from China and the U.S.
Cold atoms could replace hot gallium in focused ion beams
Nov 13, 2008 |
4.9 / 5 (14) |
0
(PhysOrg.com) -- Scientists at the National Institute of Standards and Technology have developed a radical new method of focusing a stream of ions into a point as small as one nanometer. Because of the versatility ...
Physicists demonstrate quantum entanglement in mechanical system
Jun 03, 2009 |
4.8 / 5 (14) |
3
Physicists at the National Institute of Standards and Technology have demonstrated entanglement--a phenomenon peculiar to the atomic-scale quantum world--in a mechanical system similar to those in the macroscopic ...
Ion trap quantum computing
May 12, 2009 |
4.5 / 5 (11) |
1
(PhysOrg.com) -- “Right now, classical computers are faster than quantum computers,” René Stock tells PhysOrg.com. “The goal of quantum computing is to eventually speed up the time scale of solving certain important proble ...
Site for alcohol's action in the brain discovered
Medicine & Health / Neuroscience
Jun 28, 2009 |
5 / 5 (10) |
1
Alcohol's inebriating effects are familiar to everyone. But the molecular details of alcohol's impact on brain activity remain a mystery. A new study by researchers at the Salk Institute for Biological Studies ...
'Core-Shell' Silicon Nanowires May Improve Lithium-Ion Batteries
Jan 20, 2009 |
4 / 5 (12) |
9
(PhysOrg.com) -- Researchers have found a way to incorporate silicon into the structure of rechargeable lithium-ion batteries, which are used to power a wide variety of portable electronic devices, including ...
Metal hazard from table wines
Oct 29, 2008 |
4.3 / 5 (11) |
1
Potentially hazardous levels of metal ions are present in many commercially available wines. An analysis of reported levels of metals in wines from sixteen different countries, published in the open access Chemistry Central Jo ...
