Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesAn anion is an ion with a net negative charge. It may be a single atom or a group of atoms, and the charge—not a supposed appetite for electrons—is what defines it. In the familiar case, an atom gains electrons while its number of protons stays the same, leaving more negative charges than positive ones.
What makes an ion an anion?
The International Union of Pure and Applied Chemistry (IUPAC) defines an anion as “A monoatomic or polyatomic species having one or more elementary charges of the electron.” In plain language, an anion can be one atom or several atoms acting as a charged species, and its overall charge is negative. IUPAC Gold Book: anion
As an Amazon Associate I earn from qualifying purchases.
In the introductory example of electron transfer, an atom gains one or more electrons. Electrons carry negative charge, so gaining them makes the species’ total charge more negative. The number of protons in the nucleus does not change during this ordinary ion formation; it is the balance between protons and electrons that changes. Khan Academy: ions and ionic compounds
How is an anion different from a cation?
Anions are negatively charged; cations are positively charged. Electron gain and electron loss are useful introductory ways to describe how ions form: gaining electrons can produce an anion, while losing electrons can produce a cation.
#1 Best Overall
| Ion | Net charge | Introductory electron-balance description |
|---|---|---|
| Anion | Negative | Gains electrons |
| Cation | Positive | Loses electrons |
Does gaining an electron release energy?
It depends on the species and on which direction of the process is being described. “Electron affinity” is an energy term, not another name for an anion and not a measure of an atom’s personality. IUPAC defines electron affinity in terms of the energy required to detach an electron from a singly charged negative ion; equivalently, it describes the energy released when an electron attaches to a neutral atom or molecule. State whether a value refers to attachment or detachment, and whether energy is released or required. IUPAC Gold Book: electron affinity
Why “electron-loving” is only a metaphor
Calling an atom “electron-loving” may suggest that it tends to gain electrons, but it is not a precise chemical definition. An anion is identified by its negative charge. Electron affinity describes an energy change for a specified attachment or detachment process; it should not be used as a synonym for anion or as an unqualified claim that an atom “wants” an electron.
Rank #2
When does the term “negative ion” matter?
For an atom, radical, molecule, or molecular moiety in the vapour phase after it gains electrons, IUPAC uses “negative ion” and says “anion” is not recommended as an alternative in that context because the latter carries solution-chemistry connotations. This qualification concerns gas-phase terminology; it does not rule out the ordinary use of “anion” in solution chemistry. IUPAC Gold Book: negative ion
Quick Recap
Best Value
Rank #4
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
