Science, Tech, Math › Science Inductive Effect & Resonance Share Flipboard Email Print Itamblyn//Wikipedia 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 July 03, 2019 The inductive effect and resonance both relate to the distribution of electrons in a chemical bond, but are two different and distinct bonding processes. The Inductive Effect The inductive effect, sometimes written as "the -I Effect" in literature, is the distance-dependent phenomenon by which the charge of a chemical bond affects orientation on adjacent bonds in a molecule, producing a permanent state of polarization. How It Works The electron density of a σ bond is not uniform when atoms of two different elements participate in the bond. Electron clouds in a bond tend to orient themselves toward the more electronegative atom involved in the bond. The inductive effect occurs in water molecules. The chemical bonds within a water molecule are more positively charged near the hydrogen atoms and more negatively charged near the oxygen atom. Thus, water molecules are polar. Note, however, the induced charge is weak and the inductive effect is only active across short distances, so other factors can quickly overcome it. Inductive Effect and Acidity and Basicity The inductive effect affects the stability as well as acidity or basicity of a chemical species. Electronegative atoms draw electrons toward themselves, which can stabilize a conjugate base. Groups that have -I effect on a molecule decrease its electron density, making the molecule electron deficient and more acidic. Resonance Resonance is the bonding of multiple Lewis structures within a molecule as a result of a double bond formed with equal probability between different atoms. For example, ozone (O3) has resonance forms. One might wonder whether the bond formed between one oxygen atom might be a different length from another since single bonds are usually weaker/longer than double bonds. In reality, each bond is the same length and strength because resonance forms (drawn on paper) don't represent what's really going on within the molecule -- it doesn't have a double bond and a single bond. Rather, the electrons are distributed evenly across the atoms, forming intermediate bonds between single and double bonds.