https://www.khanacademy.org/science/ap-biology/chemistry-of-life/structure-of-water-and-hydrogen-bonding/v/hydrogen-bonding-in-water 2024-05-06T19:22:43.24334365Z Hydrogen bonding in water Water is made up of two hydrogens and one oxygen atom, arranged in a tetrahedral shape. Oxygen is highly electronegative, which creates a partial negative charge on one end of the molecule, and a partial positive charge on the other. So, water molecules are able to form hydrogen bonds with one another, giving water many of its unique properties. Sal Khan video https://cdn.kastatic.org/googleusercontent/v6flhLpSALrboiHbmgvmHe2pwc8py225cKGtpBk2LtKGtkCVD2ONNWLrW-dI5ea-schvnK1ElyQtOJInviOo1AGU Hydrogen bonding in water Water is made up of two hydrogens and one oxygen atom, arranged in a tetrahedral shape. Oxygen is highly electronegative, which creates a partial negative charge on one end of the molecule, and a partial positive charge on the other. So, water molecules are able to form hydrogen bonds with one another, giving water many of its unique properties. https://cdn.kastatic.org/ka-youtube-converted/6G1evL7ELwE.mp4/6G1evL7ELwE.mp4 407 Chemical nature and significance of water https://www.khanacademy.org/science/ap-biology/chemistry-of-life/structure-of-water-and-hydrogen-bonding/e/structure-of-water-and-hydrogen-bonding-exercise 2025-08-23T06:00:52.132252272Z Structure of water and hydrogen bonding Test your understanding of the structure of water and hydrogen bonding in this set of free, CED-aligned practice questions. Ashley Mucha exercise https://www.khanacademy.org/science/ap-biology/chemistry-of-life/structure-of-water-and-hydrogen-bonding/v/water-as-a-solvent 2024-05-06T19:22:43.24334365Z Water as a solvent Water, due to its polarity, acts as a fantastic solvent, especially for polar substances and ions. This is because the positive and negative ends of water molecules are attracted to ions, allowing them to dissolve. This property is crucial for chemical interactions within cells. However, non-polar substances like hydrocarbons do not dissolve well in water and are termed hydrophobic. Sal Khan video https://cdn.kastatic.org/googleusercontent/h9UjzS82yETbQX39PdB2dOKjImlZPvzu91WtQUjgGEKEOcDPnXkTfkomm8hk0rjftAQHAiMv4VLmFBQTsLoW8GRx Water as a solvent Water, due to its polarity, acts as a fantastic solvent, especially for polar substances and ions. This is because the positive and negative ends of water molecules are attracted to ions, allowing them to dissolve. This property is crucial for chemical interactions within cells. However, non-polar substances like hydrocarbons do not dissolve well in water and are termed hydrophobic. https://cdn.kastatic.org/ka-youtube-converted/lCvBp73ZJ-A.mp4/lCvBp73ZJ-A.mp4 552 Chemical nature and significance of water 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 Chemical nature and significance of water https://www.khanacademy.org/science/ap-biology/chemistry-of-life/structure-of-water-and-hydrogen-bonding/a/cohesion-and-adhesion-in-water 2026-03-17T04:30:40.156944414Z Cohesion and adhesion of water Learn about cohesion, adhesion, and surface tension of water and how they relate to hydrogen bonding. article 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 Chemical nature and significance of water https://www.khanacademy.org/science/ap-biology/chemistry-of-life/structure-of-water-and-hydrogen-bonding/a/specific-heat-heat-of-vaporization-and-freezing-of-water 2025-08-23T06:00:52.132252272Z Specific heat, heat of vaporization, and density of water Learn about specific heat capacity and heat of vaporization of water, evaporative cooling, and why ice floats. article https://www.khanacademy.org/science/ap-biology/chemistry-of-life/structure-of-water-and-hydrogen-bonding/v/importance-of-water-for-life 2025-08-23T06:00:52.132252272Z Importance of water for life Discussion of the properties of water that make it essential to life as we know it: polarity, "universal" solvent, high heat capacity, high heat of vaporization, cohesion, adhesion and lower density when frozen. video https://cdn.kastatic.org/googleusercontent/2FOaIjyqdCGbemYQMl19OchAdpjXARhI8BHGjRx-pyeNtANhkuzfNfJzXm2su9ghyGh66qPbZS2wFUx3A7MFS2yH Importance of water for life Discussion of the properties of water that make it essential to life as we know it: polarity, "universal" solvent, high heat capacity, high heat of vaporization, cohesion, adhesion and lower density when frozen. https://cdn.kastatic.org/ka-youtube-converted/fxlMABxU7zU.mp4/fxlMABxU7zU.mp4 532 Chemical nature and significance of water https://www.khanacademy.org/science/ap-biology/chemistry-of-life/structure-of-water-and-hydrogen-bonding/a/hs-water-and-life-review 2025-08-23T06:00:52.132252272Z Lesson summary: Water and life Review key terms and the unique properties of water. article