Science, Tech, Math › Science Group Definition Chemistry Glossary Definition of Group Share Flipboard Email Print Periodic Table Close-Up. Daniel Hurst Photography/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 April 22, 2018 Group Definition: In chemistry, a group is a vertical column in the Periodic Table. Groups may be referred to either by number or by name. For example, Group 1 is also known as the Alkali Metals.