https://www.khanacademy.org/science/ms-chemistry/xc370bc422b7f75fc:chemical-changes/xc370bc422b7f75fc:chemical-reactions/v/chemical-reactions 2025-03-21T20:29:57.678923887Z Chemical reactions A chemical reaction is a process where substances, called reactants, rearrange their atoms to form new substances, known as products. No atoms are lost or gained—just rearranged. Evidence of a reaction includes color changes, gas production, or energy changes. In a closed system, the total mass of reactants and products remains the same. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/a556311b-ebbb-4584-951f-531519a2ef8a_1280_720_base.png Chemical reactions A chemical reaction is a process where substances, called reactants, rearrange their atoms to form new substances, known as products. No atoms are lost or gained—just rearranged. Evidence of a reaction includes color changes, gas production, or energy changes. In a closed system, the total mass of reactants and products remains the same. https://cdn.kastatic.org/ka-youtube-converted/a9RJZqG9qJo.mp4/a9RJZqG9qJo.mp4 261 Chemical reactions https://www.khanacademy.org/science/ms-chemistry/xc370bc422b7f75fc:chemical-changes/xc370bc422b7f75fc:chemical-reactions/v/chemical-equations 2025-03-21T20:29:57.678923887Z Chemical equations Chemical equations use symbols and formulas to represent chemical reactions. Reactants, on the left, rearrange to form products, on the right. The law of conservation of matter states that atoms cannot be created or destroyed, so equations must be balanced using coefficients to ensure the same number of each atom appears on both sides. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/d3564b9f-eec6-4925-a114-6533dffea9c2_1280_720_base.png Chemical equations Chemical equations use symbols and formulas to represent chemical reactions. Reactants, on the left, rearrange to form products, on the right. The law of conservation of matter states that atoms cannot be created or destroyed, so equations must be balanced using coefficients to ensure the same number of each atom appears on both sides. https://cdn.kastatic.org/ka-youtube-converted/_c6wm4jl8BU.mp4/_c6wm4jl8BU.mp4 485 Chemical reactions https://www.khanacademy.org/science/ms-chemistry/xc370bc422b7f75fc:chemical-changes/xc370bc422b7f75fc:chemical-reactions/a/chemical-equations 2025-11-08T16:40:48.990144768Z Chemical equations Learn how to read and interpret chemical equations that represent what happens during chemical reactions. Discover how chemical equations show the reactants that combine and the products that form, along with the story they tell about the reaction. article https://www.khanacademy.org/science/ms-chemistry/xc370bc422b7f75fc:chemical-changes/xc370bc422b7f75fc:chemical-reactions/e/understand-chemical-equations 2025-11-08T17:20:51.153278549Z Understand: chemical equations Check your understanding of chemical equations in this set of free, standards-aligned practice questions. donna fig exercise https://www.khanacademy.org/science/ms-chemistry/xc370bc422b7f75fc:chemical-changes/xc370bc422b7f75fc:chemical-reactions/e/apply-chemical-equations 2025-11-08T17:20:51.153278549Z Apply: chemical equations Apply your understanding of chemical equations in this set of free, standards-aligned practice questions. donna exercise