What is the Difference Between Radical and Ion

Radicals and ions both represent atoms or molecules that have altered electron configurations, leading to increased reactivity compared to their neutral counterparts. Understanding the difference between a radical and an ion is helpful for various scientific applications, from organic chemistry to atmospheric science.

What is the difference between radical and ion? Ions are generally more stable and less reactive than radicals.

Key Areas Covered

1. What are Radicals
      – Definition, Features 
2. What are Ions
      – Definition, Features 
3. Similarities Between Radical and Ion
      – Outline of Common Features
4. Difference Between Radical and Ion
      – Comparison of Key Differences
5. FAQ: Radical and Ion 
      – Frequently Asked Questions

Key Terms

Radical, Ion

Difference Between Radical and Ion  - Comparison Summary

What are Radicals

Radicals have an unpaired electron, which makes them highly reactive. These reactive radicals are often formed by breaking apart molecules during chemical reactions. Radicals are formed in the presence of heat, light, or even other radicals.

The lifespan of a radical is very short due to the unpaired electron, which makes it unstable. They’re constantly seeking stability, which they achieve by either stealing an electron from another molecule or donating their own. This electron exchange is the driving force behind many chemical reactions, including those involving combustion and polymerization.

Ion vs Racical

There are many roles of radicals in the body as well. Cellular respiration, the process by which we obtain energy from food, involves radical intermediates. However, when there is an excess amount of radicals that are higher than the required levels, they may cause cell damage and even certain diseases. Antioxidants found in fruits and vegetables neutralize these excess radicals.

What are Ions

Ions are atoms or molecules that have gained or lost electrons, resulting in an electrical charge. Ions can be positively charged (cations) if they lose electrons. They become negatively charged (anions) if they gain electrons. Due to this charge imbalance, they are highly reactive, making them attracted to oppositely charged ions like magnets. This attraction is the foundation of ionic bonding, the electrostatic force that holds ionic compounds together, like the familiar table salt (NaCl). Here, sodium (Na) loses an electron, becoming a positively charged cation, while chlorine (Cl) gains one, transforming into a negatively charged anion. Their opposite charges create a strong ionic bond.

One other use of ions is that they conduct electricity. Ions can move freely carrying electric current in solutions or molten states. This ionic conductivity is what makes electrolytes in batteries function and allows nerve impulses to travel in our bodies. There are many uses of ions. In medicine, calcium ions are vital for bone health, while sodium and potassium ions maintain proper fluid balance in our cells.

Similarities Between Radical and Ion

  1. Both radicals and ions have an altered electron configuration compared to their neutral counterparts.
  2. This changed electron configuration makes both radicals and ions more reactive than their neutral counterparts.
  3. Both can form through various processes that disrupt the stable electron configuration of an atom or molecule.

Difference Between Radical and Ion


  • A radical is a molecule with one or more unpaired electrons, making it highly reactive. An ion is an atom or molecule that has gained or lost electrons, resulting in a net electrical charge.


  • Radicals are mostly neutral, while ions are charged (either as positive or negative).


  •  Ions are generally more stable than radicals.


  • Radicals are often formed by breaking apart molecules during chemical reactions, exposure to light or heat, or by other radicals. Ions are formed by gaining or losing electrons due to factors like ionization energy (energy needed to remove an electron), electron affinity (attraction for electrons), or chemical reactions.


The main difference between radical and ion is in their stability and charge. Radicals have unpaired electrons, making them highly reactive and usually neutral, while ions carry a positive or negative charge due to losing or gaining electrons, respectively, and are generally more stable.

FAQ: Radical and Ion

1. Can ions be free radicals?

Yes, ions can be free radicals. When an ion has an unpaired electron, it meets the criteria to be considered a radical. So, any ion with an unpaired electron is both an ion (due to its charge) and a radical (due to its unpaired electron),

2. What are the two types of radicals?

The two types of radicals are neutral radicals and charged radicals. Neutral radicals have no net charge and have at least one unpaired electron, while charged radicals, also known as radical ions, carry a net electrical charge due to the presence of unpaired electrons.

3. What are positive and negative radicals?

Positively charged radicals are called basic radicals such as Na+, NH4+ etc., while negatively charged radicals are called acid radicals such as NO3, Cl, etc.

4. What is an example of a radical?

Hydroxyl (HO•) is an example of a radical. It consists of one hydrogen atom bonded to one oxygen atom, and it has one unpaired electron on the oxygen atom, making it highly reactive.


1. “Radical Chemistry.” Encyclopedia Britannica.
2. “Ion Physics.” Encyclopedia Britannica.

Image Courtesy:

1. “Hydroxide vs hydroxyl”  By Pillsmarch – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Ionic Bonding” By EliseEtc / vectorised from Ionic bonding.png – Own work (CC BY-SA 3.0) via Commons Wikimedia

About the Author: Hasini A

Hasini is a graduate of Applied Science with a strong background in forestry, environmental science, chemistry, and management science. She is an amateur photographer with a keen interest in exploring the wonders of nature and science.

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