https://www.khanacademy.org/science/ms-chemistry/xc370bc422b7f75fc:physical-properties-of-matter/xc370bc422b7f75fc:intrinsic-and-extrinsic-properties/v/physical-changes 2025-02-13T17:59:34.347326855Z Physical changes Physical changes alter the appearance or state of matter without changing its identity. Whether bending copper wire, crushing salt, freezing water, or dissolving salt into water, the substances retain their original forms, like H₂O or NaCl. Understanding physical changes helps identify substances through properties like melting and boiling points, which are inherent and consistent across samples. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/d873dd6b-08cf-4f7e-8fc0-4d02e97127ad_1280_720_base.png Physical changes Physical changes alter the appearance or state of matter without changing its identity. Whether bending copper wire, crushing salt, freezing water, or dissolving salt into water, the substances retain their original forms, like H₂O or NaCl. Understanding physical changes helps identify substances through properties like melting and boiling points, which are inherent and consistent across samples. https://cdn.kastatic.org/ka-youtube-converted/jn-skkO5NNI.mp4/jn-skkO5NNI.mp4 318 Types of physical and chemical changes 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 Types of physical and chemical changes https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:physical-and-chemical-changes/x0c8b40bd4b242f0b:physical-and-chemical-changes-with-examples/v/melting-wax-vs-burning-candle 2023-06-26T04:10:39.513125705Z Melting wax vs Burning candle Let's identify which one's a physical change and which one's a chemical change! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Melting wax vs Burning candle Let's identify which one's a physical change and which one's a chemical change! https://cdn.kastatic.org/ka-youtube-converted/ihInc2txR2E.mp4/ihInc2txR2E.mp4 275 Types of physical and chemical changes https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:physical-and-chemical-changes/x0c8b40bd4b242f0b:physical-and-chemical-changes-with-examples/v/salt-in-water-vs-burning-magnesium 2023-06-26T04:10:39.513125705Z Salt in water vs Burning magnesium Which one's a physical change and which one's a chemical change? We have two cases here, dissolved salt in water and burning magnesium. Let's find out! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Salt in water vs Burning magnesium Which one's a physical change and which one's a chemical change? We have two cases here, dissolved salt in water and burning magnesium. Let's find out! https://cdn.kastatic.org/ka-youtube-converted/mkNIwnQcQf8.mp4/mkNIwnQcQf8.mp4 196 Types of physical and chemical changes https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:physical-and-chemical-changes/x0c8b40bd4b242f0b:physical-and-chemical-changes-with-examples/v/heating-iron-vs-rusting-iron 2023-06-26T04:10:39.513125705Z Heating iron vs rusting iron Which one's a physical change and which one's a chemical change? We have two cases here, heating iron and rusting of iron. Let's find out! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Heating iron vs rusting iron Which one's a physical change and which one's a chemical change? We have two cases here, heating iron and rusting of iron. Let's find out! https://cdn.kastatic.org/ka-youtube-converted/myVAl8ThR80.mp4/myVAl8ThR80.mp4 112 Types of physical and chemical changes https://www.khanacademy.org/science/revision-term-1-ka-science-class-7/x05832cca8e86a1ef:week-2/x05832cca8e86a1ef:physical-and-chemical-changes/v/deformation-vs-food-spoilage 2023-06-26T04:10:39.513125705Z Deformation vs Food Spoilage Which one's a physical change and which one's a chemical change? We have two cases here, deformation of a solid and spoilage of food. Let's find out! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Deformation vs Food Spoilage Which one's a physical change and which one's a chemical change? We have two cases here, deformation of a solid and spoilage of food. Let's find out! https://cdn.kastatic.org/ka-youtube-converted/Gmur3Q9M0PA.mp4/Gmur3Q9M0PA.mp4 149 Types of physical and chemical changes https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:physical-and-chemical-changes/x0c8b40bd4b242f0b:physical-and-chemical-changes-with-examples/v/dissolving-sugar-vs-burning-sugar 2023-06-26T04:10:39.513125705Z Dissolving sugar vs Burning sugar Which one's a physical change and which one's a chemical change? We have two cases here, Dissolving sugar and burning sugar. Let's find out! Vibhor Pandey video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Dissolving sugar vs Burning sugar Which one's a physical change and which one's a chemical change? We have two cases here, Dissolving sugar and burning sugar. Let's find out! https://cdn.kastatic.org/ka-youtube-converted/OLoofqhK2GM.mp4/OLoofqhK2GM.mp4 134 Types of physical and chemical changes https://www.khanacademy.org/science/revision-term-1-ka-science-class-7/x05832cca8e86a1ef:week-2/x05832cca8e86a1ef:physical-and-chemical-changes/e/difference-between-physical-and-chemical-changes 2025-04-16T07:50:43.571832077Z What is a physical and chemical change? Let's solve some questions on the physical and chemical changes   Vibhor Pandey exercise https://www.khanacademy.org/science/class-7-science/x0c8b40bd4b242f0b:physical-and-chemical-changes/x0c8b40bd4b242f0b:physical-and-chemical-changes-with-examples/e/physical-and-chemical-change 2026-03-27T14:53:23.229071668Z Physical and chemical changes Let's practice to differentiate between a physical change and a chemical change by solving the given questions. exercise https://www.khanacademy.org/science/revision-term-1-ka-science-class-7/x05832cca8e86a1ef:week-2/x05832cca8e86a1ef:physical-and-chemical-changes/e/physical-and-chemical-changes-in-daily-life 2026-04-07T22:59:30.107127435Z Identify if a change is physical or chemical Let's solve some questions on distinguishing physical and chemical changes in daily life Vibhor Pandey exercise