Science, Tech, Math › Science Mole Definition in Chemistry Print artpartner-images, Getty Images Science Chemistry Basics Chemical Laws 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. 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. Learn about our Editorial Process Updated on July 03, 2019 A Mole is defined as a chemical unit, defined to be 6.022 x 1023 (Avogadro's Constant) entities. In science, this is usually molecules or atoms. The mass of a mole is the gram formula mass of a substance. Read More Molecules and Moles in Chemistry By Anne Marie Helmenstine, Ph.D. Examples: 1 mole of NH3 has 6.022 x 1023 molecules and weighs about 17 grams (Nitrogen's molecular weight is 14 and Hydrogen is 1, 14 + 3 = 17). 1 mole of copper has 6.022 x 1023 atoms and weighs about 63.54 grams. Cite this Article Format mla apa chicago Your Citation Helmenstine, Anne Marie, Ph.D. "Mole Definition in Chemistry." ThoughtCo, Aug. 28, 2020, thoughtco.com/mole-definition-in-chemistry-606377. Helmenstine, Anne Marie, Ph.D. (2020, August 28). Mole Definition in Chemistry. Retrieved from https://www.thoughtco.com/mole-definition-in-chemistry-606377 Helmenstine, Anne Marie, Ph.D. "Mole Definition in Chemistry." ThoughtCo. https://www.thoughtco.com/mole-definition-in-chemistry-606377 (accessed April 27, 2024). copy citation