ionic bond

[ ahy-on-ik bond ]
/ aɪˈɒn ɪk ˈbɒnd /
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Definition of ionic bond

noun Chemistry.
the electrostatic bond between two ions formed through the transfer of one or more electrons.


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Also called electrovalence, e·lec·tro·va·lent bond [ih-lek-troh-vey-luhnt bond] /ɪˌlɛk troʊˈveɪ lənt ˈbɒnd/ .

Origin of ionic bond

First recorded in 1935–40
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022


What is an ionic bond?

An ionic bond is a chemical bond formed when one atom gives up one or more electrons to another atom. Ionic bonds are also known as electrovalent bonds.

Everything in the universe is made of atoms, the smallest possible form of an element. Elements include substances like oxygen, nitrogen, and carbon. Atoms are made of a nucleus (a core or center) that contains particles called protons and outer shells made of electrons.

An atom always has an equal number of protons and electrons. However, atoms want to have an outermost shell that is completely full of electrons. It can do this by taking electrons from the shells of other atoms or by giving away electrons until it loses its outermost shell and a full inner shell takes its place.

For example, the sodium atom has an outer shell with only 1 electron, which it wants to get rid of. The chlorine atom has an outer shell with 7 electrons and only needs one more to fill its shell. So, the chlorine atom will take the sodium’s electron and both atoms are happy.

However, the sodium atom now has more protons than electrons. Because protons have a positive charge, the sodium atom now has a positive charge. The chlorine atom now has more electrons, which have a negative charge, than protons, so it now has a negative charge. As with magnets, positive and negative charges in atoms are attracted to each other. The charged sodium and chlorine atoms become attracted to each other and form a bond. This charged bond is known as an ionic bond.

By forming an ionic bond, the sodium and chlorine are not separate atoms anymore. They have formed a molecule, which is the name of a substance formed from the combination of atoms. In this case, the molecule that has been created is NaCl, known as sodium chloride or, more commonly, table salt.

Why is ionic bond important?

The first records of the term ionic bond come from around 1935. The term combines the word ionic, which describes electrically charged atoms, and bond, something that holds things together. Ionic bonds hold two atoms together using electrical charges. Actual ionic bonds are part of nature and have most likely existed as long as the universe itself has.

The electrically charged atoms that make up an ionic bond are known as ions, which is where the bond’s name ultimately comes from. The positively charged atom is called a cation, and a negatively charged atom is called an anion.

A substance made up of multiple molecules is known as a compound. A compound made from molecules linked by ionic bonds is called an ionic compound. There are many examples of ionic compounds, both created by nature and made by humans, such as table salt (NaCl), rock salt (CaCl2), toothpaste fluoride (NaF), and rust (Fe2O3).

Did you know … ?

Ionic bonds can be very strong or very weak, depending on the size and electrical strength of the ions that make them up. However, ionic bonds are almost always very weak in liquids or in solids that dissolve in water. This is because the atoms are free to move around and can split from each other if they are attracted to stronger charges.

What are real-life examples of ionic bond?

Ionic bonds are often one of the first things students learn about when studying chemistry.


What other words are related to ionic bond?

Quiz yourself!

True or False?

An ionic bond is formed when two atoms share an electron.

How to use ionic bond in a sentence

British Dictionary definitions for ionic bond

ionic bond

another name for electrovalent bond
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for ionic bond

ionic bond
[ ī-ŏnĭk ]

A chemical bond formed between two ions with opposite charges. Ionic bonds form when one atom gives up one or more electrons to another atom. These bonds can form between a pair of atoms or between molecules and are the type of bond found in salts.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

Cultural definitions for ionic bond

ionic bond
[ (eye-on-ik) ]

A chemical bond in which one atom gives up an electron to another, thereby generating an electrical force that holds the atoms together.

notes for ionic bond

Many crystals are held together by ionic bonds.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.