If an atom, or atoms, has actually a balanced variety of electrons (negative charge) and also protons (positive charge) they are neutral overall. However, if they room not balanced, they will certainly be charged. This charged types are called ions.

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What is a cation?

A cation has an ext protons 보다 electrons, consequently giving it a net hopeful charge. For a cation to form, one or an ext electrons need to be lost, commonly pulled far by atoms through a stronger affinity because that them. The number of electrons lost, and so the fee of the ion, is indicated after the chemical symbol, e.g. Silver (Ag) loses one electron to become Ag+, whilst zinc (Zn) loses 2 electrons to become Zn2+.



What is an anion?

An anion has much more electrons than protons, consequently providing it a net negative charge. Because that an anion come form, one or more electrons should be gained, generally pulled far from various other atoms with a weaker affinity for them. The variety of electrons gained, and also so the fee of the ion, is shown after the chemistry symbol, e.g. Chlorine (Cl) profit one electron to come to be Cl-, whilst oxygen (O) gains 2 electrons to come to be O2-.


Cation vs anion chart

The key differences between cations and anions room summarized in the table below.






Electrode attracted to

Cathode (negative)

Anode (positive)

Formed by

Metal atoms

Non-metal atoms


Sodium (Na+), iron (Fe2+), Ammonium (NH4+)

Chloride (Cl-), Bromide (Br-), Sulfate (SO42-)

Metallic atoms organize some of your electrons relatively loosely. Consequently, they tend to shed electrons and kind cations. Conversely, most nonmetallic atoms attract electrons an ext strongly than metallic atoms, and also so acquire electrons to form anions. Therefore, as soon as atoms from a metallic and a nonmetallic facet combine, the nonmetallic atoms have tendency to draw one or an ext electrons away from the metallic atom to form ions. This oppositely charged ion then tempt one other to kind ionic bonds and produce ionic compounds v no in its entirety net charge. Examples include calcium chloride (CaCl2), potassium iodide (KI) and also magnesium oxide (MgO).

Cation vs anion regular table

It have the right to be possible to predict whether an atom will type a cation or an anion based on its place on the regular table. Halogens always kind anions, alkali metals and also alkaline planet metals always form cations. Most other metals kind cations (e.g. Iron, silver, nickel), whilst many other nonmetals typically kind anions (e.g. Oxygen, carbon, sulfur). However, some aspects are qualified of developing both cations and anions provided the appropriate conditions. One example is hydrogen, i m sorry may acquire (H-) or lose (H+) an electron, forming hydride compounds such together ZnH2 (where it is an anion) and hydron link such as H2O (where it is a cation).

Elements in team 18 the the periodic table – the “noble gases”, tend not to kind ions because of the plan of their electrons which provides them normally unreactive.


Cation vs anion size

Cations and anions come in countless sizes across the routine table, as seen in this video.

Utilizing ionic properties

Ionic properties have the right to be exploited by chemists for a variety of purposes. Ion-exchange chromatography for example relies top top the affinity the the molecules gift separated for the stationary phase based upon their charge properties to allow separation.

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Ionic properties are main to the role of battery too. Batteries have two electrodes do of conductive material, the cathode i m sorry is the positive end where the electrical current leaves/electrons enter, and the anode wherein the electrical existing enters/ electron leave. In in between the electrodes is one electrolyte fluid or gelatin that has charged corpuscle – ions. As this ionic problem reacts with the electrodes the generates electric current. In solitary use, dried cell batteries, zinc is commonly used as the anode whilst manganese dioxide is a popular an option for the electrolyte cathode. The zinc anode also acts as the battery’s container in zinc-carbon batteries so as it oxidizes throughout use, the contents can begin to leak over time.