https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:chemical-reactions/x2613d8165d88df5e:representing-chemical-reactions/v/physical-and-chemical-changes 2023-12-15T18:39:28.793791463Z Physical and chemical changes Physical and chemical processes can be classified by the changes occurring on the molecular level. In general, chemical processes involve changes in chemical bonds, while physical processes involve changes only in intermolecular forces. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/13f405e4-0927-4fb9-9b5e-913f069d17f9_1280_720_base.png Physical and chemical changes Physical and chemical processes can be classified by the changes occurring on the molecular level. In general, chemical processes involve changes in chemical bonds, while physical processes involve changes only in intermolecular forces. https://cdn.kastatic.org/ka-youtube-converted/n5cZ5CWuUJA.mp4/n5cZ5CWuUJA.mp4 279 Chemical bonding https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atomic-models-and-periodicity/x2613d8165d88df5e:the-periodic-table/a/determine-valence-electrons-using-the-periodic-table 2026-04-26T16:30:39.382257956Z Learn: Determine valence electrons using the periodic table Learn how to determine the number of valence electrons for an element using the periodic table. article https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:atomic-models-and-periodicity/x2613d8165d88df5e:the-periodic-table/e/apply-number-of-valence-electrons 2026-06-25T10:00:38.725739878Z Apply: Number of valence electrons Apply your understanding of valence electrons for main group elements in this set of free, standards-aligned practice questions. Emily Cizmas exercise