Science, Tech, Math › Science Van der Waals Radius Definition What Is the Van der Waals Radius in Chemistry? Share Flipboard Email Print The van der Waals radius is half the distance between two nonbonded atoms at their closest approach. Stanislaw Pytel / Getty Images Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated January 30, 2019 The Van der Waals radius is equal to one half the distance between two unbonded atoms when the electrostatic forces between them are balanced. In other words, it is half of the closest distance between two atoms that aren't bonded or within the same molecule. Picometers (pm) are typically the unit used to report the value. The distance reflects the action of intermolecular forces (e.g., dipole-dipole and dispersion forces) and is related to van der Waals interactions. Knowing the van der Waals radius is helpful when predicting how closely atoms will pack to form a solid. Sample Van der Waals Radius Values Element radius (pm) H 120 B 208 C 185 N 154 O 140 F 135 Cl 180 Br 195 I 215 He 99 Reference Housecroft. Inorganic Chemistry. 2008. Cite this Article Format mla apa chicago Your Citation Helmenstine, Anne Marie, Ph.D. "Van der Waals Radius Definition." ThoughtCo, Aug. 27, 2020, thoughtco.com/definition-of-van-der-waals-radius-605939. Helmenstine, Anne Marie, Ph.D. (2020, August 27). Van der Waals Radius Definition. Retrieved from https://www.thoughtco.com/definition-of-van-der-waals-radius-605939 Helmenstine, Anne Marie, Ph.D. "Van der Waals Radius Definition." ThoughtCo. https://www.thoughtco.com/definition-of-van-der-waals-radius-605939 (accessed September 22, 2021). copy citation Polar Bond Definition and Examples Van der Waals Forces: Properties and Components The 5 Main Branches of Chemistry Ionic Radius Definition and Trend 3 Types of Intermolecular Forces A to Z Chemistry Dictionary Dipole Moment Definition Heat Capacity Definition Clickable Periodic Table of the Elements Topics Typically Covered in Grade 11 Chemistry Atomic Radius Definition and Trend Raoult's Law Definition in Chemistry What Is the Difference Between Atomic Radius and Ionic Radius? Covalent Radius Definition Gases Study Guide What Is the Most Ideal Gas?