Science, Tech, Math › Science Electron Cloud Definition Understand the Electron Cloud Model Share Flipboard Email Print The electron cloud is the location around the nucleus that contains negatively-charged electrons. Yzmoderivative/CC-BY-SA-3.0/Wikimedia Commons 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 December 09, 2019 An electron cloud is the region of negative charge surrounding an atomic nucleus that is associated with an atomic orbital. It is defined mathematically, describing a region with a high probability of containing electrons. The phrase "electron cloud" first came into use around 1925, when Erwin Schrödinger and Werner Heisenberg were seeking for a way to describe the uncertainty of the position of electrons in an atom. Electron Cloud Model The electron cloud model differs from the more simplistic Bohr model, in which electrons orbit the nucleus in much the same way as planets orbit the sun. In the cloud model, there are regions where an electron may likely be found, but it's theoretically possible for it to be located anywhere, including inside the nucleus. Chemists use the electron cloud model to map out the atomic orbitals for electrons; these probability maps are not all spherical. Their shapes help predict the trends seen in the periodic table.