https://www.khanacademy.org/science/grade-6-science-snc-aligned/x19bc096754f0b9af:matter-as-particles/x19bc096754f0b9af:particle-theory-and-states-of-matter/v/characteristics-of-particles-of-matter-ur 2025-08-07T23:35:51.501752344Z Characteristics of particles of matter Created by Khan Academy video https://cdn.kastatic.org/googleusercontent/ZCdwTudJg6e6n-P2gsaUborP4izvMsGo71pvEVlX9dNYWcLXcP7VHkWpn2grt4TUP1KoJLQP9NswyHBuBLSFTBw Characteristics of particles of matter Created by Khan Academy https://cdn.kastatic.org/ka-youtube-converted/N56mq4it4JI.mp4/N56mq4it4JI.mp4 328 Properties of the liquid state https://www.khanacademy.org/science/ap-biology/chemistry-of-life/structure-of-water-and-hydrogen-bonding/v/surface-tension 2023-04-30T21:01:15.828786566Z Surface tension Water molecules are held together by hydrogen bonds, which give water its unique properties. At the surface of water, molecules are more densely packed because they are not being pulled from above, resulting in stronger intermolecular forces. This creates surface tension, which allows for phenomena such as water droplets maintaining a round shape and insects walking on water. video https://cdn.kastatic.org/googleusercontent/DP7DPndX6MRHR76u4zj2nWlYzwXwNXrKgbXN4vgPUyilPKw7af2QFnQgeyMZhMZB1uQok7iYBqD-sypBz3EJnIk Surface tension Water molecules are held together by hydrogen bonds, which give water its unique properties. At the surface of water, molecules are more densely packed because they are not being pulled from above, resulting in stronger intermolecular forces. This creates surface tension, which allows for phenomena such as water droplets maintaining a round shape and insects walking on water. https://cdn.kastatic.org/ka-youtube-converted/_RTF0DAHBBM.mp4/_RTF0DAHBBM.mp4 271 Properties of the liquid state https://www.khanacademy.org/science/grade-11-chemistry-snc-aligned/x203b0fc81a964b2d:sates-and-phases-of-matter/x203b0fc81a964b2d:unique-properties-of-water/v/surface-tension-ms 2025-05-07T17:11:10.976262835Z Surface tension Cohesion causes water particles to attract and hold together, leading to fascinating effects like surface tension. At the surface, water molecules pull inward, creating a "skin" that's stronger than the liquid below. This tension allows water striders to walk on water and paperclips to float, highlighting the unique behavior of water’s cohesive forces. Mahesh Shenoy video https://cdn.kastatic.org/ka_thumbnails_cache/ebe30a3c-c707-46d3-9c79-bce209d97514_1280_720_base.png Surface tension Cohesion causes water particles to attract and hold together, leading to fascinating effects like surface tension. At the surface, water molecules pull inward, creating a "skin" that's stronger than the liquid below. This tension allows water striders to walk on water and paperclips to float, highlighting the unique behavior of water’s cohesive forces. https://cdn.kastatic.org/ka-youtube-converted/4ELxJ53mMHE.mp4/4ELxJ53mMHE.mp4 313 Properties of the liquid state https://www.khanacademy.org/science/ap-biology/chemistry-of-life/structure-of-water-and-hydrogen-bonding/v/capillary-action-and-why-we-see-a-meniscus 2025-07-30T13:17:28.990785461Z Capillary action and why we see a meniscus A meniscus is a curved liquid surface that results from the interplay of adhesion (the liquid's attraction to its container) and cohesion (the liquid's attraction to itself). Adhesion also drives capillary action, which draws a liquid up a narrow tube. video https://cdn.kastatic.org/googleusercontent/GcYBBVjS_-p2iwyhKPbdGPS8FjspWai1o5ZToJZyUTsr3rv9vCE2ScIgURtcq6S_AgKVrlrKd1HRs84b-Kx-MvtTtw Capillary action and why we see a meniscus A meniscus is a curved liquid surface that results from the interplay of adhesion (the liquid's attraction to its container) and cohesion (the liquid's attraction to itself). Adhesion also drives capillary action, which draws a liquid up a narrow tube. https://cdn.kastatic.org/ka-youtube-converted/eQXGpturk3A.mp4/eQXGpturk3A.mp4 506 Properties of the liquid state https://www.khanacademy.org/science/chemistry/states-of-matter-and-intermolecular-forces/states-of-matter/v/vapor-pressure 2021-04-15T14:55:08Z Vapor pressure Vapor pressure, volatility, and evaporation. Sal Khan video https://cdn.kastatic.org/googleusercontent/Xcbhi-CrgDtzILJGS9TkjTMm1EaGOML8HEtPWXZhToZHdXty6novP08OFMg6HYn7_6pCWYpP45aF9mXm91LfrSjS Vapor pressure Vapor pressure, volatility, and evaporation. https://cdn.kastatic.org/ka-youtube-converted/hA5jddDYcyg.mp4/hA5jddDYcyg.mp4 1084 Properties of the liquid state https://www.khanacademy.org/science/chemistry/states-of-matter-and-intermolecular-forces/introduction-to-intermolecular-forces/v/boiling-points-of-organic-compounds 2021-01-04T18:35:20Z Boiling points of organic compounds How to analyze the different boiling points of organic compounds using intermolecular forces video https://cdn.kastatic.org/googleusercontent/q7cyV5iXMcmfVPASfJ0zkZvdaLfmPJWwOVo4HoHVWRWmgd_C_RVpwalleFfFE2zOyIbtTX1LXbOhHQq259uwrnk3-Q Boiling points of organic compounds How to analyze the different boiling points of organic compounds using intermolecular forces https://cdn.kastatic.org/ka-youtube-converted/pILGRZ0nT4o.mp4/pILGRZ0nT4o.mp4 667 Properties of the liquid state https://www.khanacademy.org/science/chemistry/states-of-matter-and-intermolecular-forces/introduction-to-intermolecular-forces/v/boiling-points-ap-chemistry-multiple-choice-sample 2021-01-04T18:35:20Z Boiling point comparison: AP Chemistry multiple choice Comparing the boiling point of nonane and 2,3,4-trifluoropentane. A sample multiple choice problem from the 2014 AP course description. video https://cdn.kastatic.org/googleusercontent/3mKLXEaL1rzwFS4lFWBjFCLowqb3cnMevBIr8cIjcoDBKkie5mZCeibKJS8e2u_44PqgKVwVIYWIeC2L8dS0q-52 Boiling point comparison: AP Chemistry multiple choice Comparing the boiling point of nonane and 2,3,4-trifluoropentane. A sample multiple choice problem from the 2014 AP course description. https://cdn.kastatic.org/ka-youtube-converted/JRxFsmvsmHY.mp4/JRxFsmvsmHY.mp4 379 Properties of the liquid state https://www.khanacademy.org/science/hs-chemistry/x2613d8165d88df5e:solutions-acids-and-bases/x2613d8165d88df5e:solubility/v/solubility-and-intermolecular-forces 2024-06-28T20:36:37.988994093Z Solubility and intermolecular forces Substances with similar polarities tend to be soluble in one another ("like dissolves like"). Nonpolar substances are generally more soluble in nonpolar solvents, while polar and ionic substances are generally more soluble in polar solvents. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/9170e433-65b5-4632-9283-a8adcfa45729_1280_720_base.png Solubility and intermolecular forces Substances with similar polarities tend to be soluble in one another ("like dissolves like"). Nonpolar substances are generally more soluble in nonpolar solvents, while polar and ionic substances are generally more soluble in polar solvents. https://cdn.kastatic.org/ka-youtube-converted/ccDKr4TIWfk.mp4/ccDKr4TIWfk.mp4 263 Properties of the liquid state https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:intermolecular-forces-and-properties/x2eef969c74e0d802:intermolecular-forces/e/intermolecular-forces-and-properties-of-liquids 2026-05-04T07:50:51.861128514Z Intermolecular forces and properties of liquids Check your understanding of how intermolecular forces are related to boiling point and vapor pressure in this set of free practice questions designed for AP Chemistry students. Lauren Rosebrugh exercise