Unique underpinnings revealed for stomach's acid pump

Nagoya University researchers and colleagues have improved understanding of the molecular mechanisms of a key protein that makes the stomach acidic. Their findings, published in the journal Nature Communications, could lead ...

How the Sun's magnetic forces arrange gas particles

Solar prominences hover above the visible solar disk like giant clouds, held there by a supporting framework of magnetic forces, originating from layers deep within the Sun. The magnetic lines of force are moved by ever-present ...

Examining the origins of proton spin

Where does the proton get its spin? This question has puzzled physicists ever since experiments in the 1980s revealed that a proton's constituent quarks—the most fundamental building blocks of atomic nuclei—account for ...

How mussels make a powerful underwater glue

Blue mussels (Mytilus edulis) spend their days being buffeted by crashing waves. They manage to stay tethered to the rocks or their fellow mussels thanks to a highly effective underwater glue they produce. Because achieving ...

Particle accelerators may get a boost from oxygen

Whipping up world-class particle accelerator structures has long been a process akin to following a favorite recipe. Many of the best-performing samples are prepared using processes developed through trial and error over ...

New membrane to make fresh water

Scientists at Sandia National Laboratories and their collaborators have developed a new membrane, whose structure was inspired by a protein from algae, for electrodialysis that could be used to provide fresh water for farming ...

page 1 from 40

Ion

An 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.

This text uses material from Wikipedia, licensed under CC BY-SA