Science, Tech, Math › Science What Is an Emission Spectrum in Science? Share Flipboard Email Print MirageC / 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 August 02, 2019 In general, an emission spectrum describes the wavelengths of the electromagnetic spectrum emitted by an energetic object. What this object is depends on the scientific discipline. In chemistry, an emission spectrum refers to the range of wavelengths emitted by an atom or compound stimulated by either heat or electric current. An emission spectrum is unique to each element. The emission spectrum of burning fuel or other molecules may also be used to example its composition. In astronomy, the emission spectrum generally refers to the spectrum of a star, nebula, or another body. How an Emission Spectrum Is Produced When an atom or molecule absorbs energy, electrons are bumped into a higher energy state. When the electron drops to a lower energy state, a photon is released equal to the energy between the two states. There are multiple energy states available to an electron, so there are many possible transitions, leading to the numerous wavelengths that comprise the emission spectrum. Because each element has a unique emission spectrum, the spectrum obtained from any hot or energetic body may be used to analyze its composition.