Mars atmosphere well protected from the solar wind

Despite the absence of a global Earth-like magnetic dipole, the Martian atmosphere is well protected from the effects of the solar wind on ion escape from the planet. New research shows this using measurements from the Swedish ...

Researchers charge ahead to develop better batteries

Batteries die at the most inconvenient times. Cellphones go dark during important conversations because a battery hasn't been recharged. Or the automotive industry revs up with excitement for a new battery-powered vehicle, ...

Scientists reveal the hidden costs of cobalt mining in DR Congo

In recent years, the demand for cobalt, a crucial component of rechargeable lithium-ion batteries for smartphones and electric cars, has been on the increase. Around 60 percent of the world's cobalt supply comes from the ...

New way to bump off ticks: Dry up their saliva

Saliva from a tick's bite can transmit pathogens that cause serious illnesses, such as Lyme disease, and significant agricultural losses. Current insecticides have drawbacks, so scientists have been seeking new ways to prevent ...

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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