https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-reactions/x2613d8165d88df5e:representing-chemical-reactions/v/intro-to-chemical-reactions-chemical-equation-and-reactions-chemistry-khan-academy 2026-04-08T23:10:43.121622596Z Intro to chemical equations Bonds between atoms or molecules are formed and/or broken during chemical reactions. Reactants are the inputs of a chemical reaction, and products are the outputs. Sal Khan video https://cdn.kastatic.org/googleusercontent/Z75oD-cJiGwdzgfe95kVhOnyPxF8KNuBGQi7d-Ap3DODJyIvHBOSqYwhAfUwvnRe4fqwLMRjq-YdEXlqakSM_ws Intro to chemical equations Bonds between atoms or molecules are formed and/or broken during chemical reactions. Reactants are the inputs of a chemical reaction, and products are the outputs. https://cdn.kastatic.org/ka-youtube-converted/1wQqGFebxyA.mp4/1wQqGFebxyA.mp4 344 Chemical reactions https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-reactions/x2613d8165d88df5e:representing-chemical-reactions/e/apply-representing-chemical-reactions 2026-03-02T06:20:38.576309557Z Apply: representing chemical reactions Apply your understanding of using chemical equations to represent chemical reactions in this set of free practice questions. Fig exercise https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-reactions/x2613d8165d88df5e:representing-chemical-reactions/e/apply-counting-atoms-in-chemical-equations 2024-03-08T16:11:13.121317577Z Apply: counting atoms in chemical equations Apply your understanding of subscripts and coefficients in chemical equations in this set of free practice questions. Fig exercise https://www.khanacademy.org/science/ms-chemistry/xc370bc422b7f75fc:chemical-changes/xc370bc422b7f75fc:chemical-changes-ms/v/chemical-changes 2025-03-21T20:29:57.678923887Z Chemical changes A chemical change occurs when a substance transforms into one or more new substances with different properties. Chemical reactions often involve color changes, gas production, odor changes, precipitate formation, or energy changes like heat or light. Unlike physical changes, chemical changes alter a substance’s identity, making them key to understanding chemical properties. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/3665da2c-e708-41b0-a732-779264ca6d87_1280_720_base.png Chemical changes A chemical change occurs when a substance transforms into one or more new substances with different properties. Chemical reactions often involve color changes, gas production, odor changes, precipitate formation, or energy changes like heat or light. Unlike physical changes, chemical changes alter a substance’s identity, making them key to understanding chemical properties. https://cdn.kastatic.org/ka-youtube-converted/CT5CVpOVAoY.mp4/CT5CVpOVAoY.mp4 445 Chemical reactions