We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Finance

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is Bond Order?

By Richard Jennings
Updated: Feb 25, 2024
Views: 16,053
Share

A bond order is the measure of the number of bonding electron pairs in a molecule. It is used as a relativistic index for judging the strength of molecular bonds. Although the methods of calculation vary, bond order is almost always a number between 1 and 3, with 3 being the strongest. Bond orders have a variety of practical applications in the field of Chemistry. Manufacturers of novelty chemicals can use bond-order calculations to judge the relative stability of the molecules they create. Most notably perhaps, bond orders have been used in the creation of super alloys, such as single crystal-based nickel.

Bond orders have always been an important part of chemistry; the most modern understanding of bond order, however, was made possible by the Molecular Orbital Theory. This theory, introduced by scientists Frederich Hund, Robert Mulliken, John C. Slater, and John Leonard-Jones, was the first to accurately describe simple and elegant calculations for determining bond orders. The calculations were derived from the essential tenants of molecular bond theory which established that bonding orbitals strengthen bonds, while anti-bonding orbitals weaken the bonds, in equal proportions. The theory also described how orbitals closest to the nuclei are incapable of influencing bond strength, which contributed to a grander perspective in quantum mechanics that previous theories were not able to achieve.

Calculating bond orders using Molecular Orbital Theory is fairly basic. Bond order equals the number of bonding electrons minus the number of anti-bonding electrons, and that sum is divided by two. To find the number of bonding and anti-bonding electrons, one can use an electron configuration, accounting for sigma and pi bonds.

Interpreting the index number is basic as well. A bond order of zero indicates that the bond is unstable. A bond order of one indicates a stable bond, and a bond order of 2 indicates that a bond is not easily broken. Bonds with an order of 3 are considered very strong. Highly stable bond orders are usually very long, covalent bonds. For instance, diamond — one of the strongest natural substances on the earth — is entirely made of carbon and has very long bond length of 154 picometers, or 154 trillionths of a meter. Since diamond is made purely of carbon, and bonds between multiple carbon atoms are almost always double bonds — bond order 2 — it is naturally very strong.

Share
WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Editors' Picks

Discussion Comments
Share
https://www.wise-geek.com/what-is-bond-order.htm
Copy this link
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.