{"id":9589,"date":"2026-06-01T21:33:48","date_gmt":"2026-06-01T21:33:48","guid":{"rendered":"https:\/\/kapdec.com\/help\/?p=9589"},"modified":"2026-06-01T21:33:48","modified_gmt":"2026-06-01T21:33:48","slug":"structure-of-water-and-hydrogen-bonding","status":"publish","type":"post","link":"https:\/\/kapdec.com\/help\/structure-of-water-and-hydrogen-bonding\/","title":{"rendered":"Structure Of Water And Hydrogen Bonding"},"content":{"rendered":"

Reference: <\/em><\/strong>AP Course Bio Unit 1, Chemistry of Life, Structure of water, Hydrogen bonding, Atomic structure, Vander-Waals interaction, Polarity of water,  Water properties, Cohesion and adhesion of water molecules.<\/em><\/h4>\n

 <\/p>\n

Learning objectives<\/strong><\/h2>\n
    \n
  • \n

    To study previous knowledge of chemistry<\/p>\n<\/li>\n

  • \n

    To understand the structure of water and bonding in it<\/p>\n<\/li>\n<\/ul>\n

    CHEMISTRY OF LIFE <\/strong><\/h2>\n

    ATOM<\/strong>-The smallest unit of an element<\/p>\n

    SUBATOMIC PARTICLES<\/strong><\/p>\n

      \n
    • Proton – Subatomic particles that carry a positive charge. They are in the nucleus of an atom. The number of protons defines the atomic number of the element.<\/li>\n
    • Neutron – These particles carry NO charge (are neutral). They are also located in the nucleus of an atom<\/li>\n
    • Electrons – These subatomic particles carry a negative charge.<\/li>\n<\/ul>\n

      MOLECULE- <\/strong>Two or more atoms that are covalently bonded together.<\/p>\n

      VALENCE SHELL<\/strong>– Where the outer most electrons are located on an atom.<\/p>\n

      VALENCE ELECTRONS<\/strong>– Refers to the outermost electrons.<\/p>\n

      CHEMICAL BONDS<\/strong> (These occur between atoms.)<\/p>\n

        \n
      • Covalent Bonds<\/strong>– are formed by the sharing of electrons<\/li>\n
      • Polar molecules carry a slight electrical charge at opposite poles (poles refers to the “ends” of the molecule) and non-polar molecules do not have an electrical charge.<\/li>\n
      • Electronegativity- Refers to an atom’s desire to acquire electrons.<\/li>\n
      • Ionic Bonds-<\/strong>formed by gain of electrons. Compounds held together by ionic bonds are called salts.<\/li>\n<\/ul>\n

        HYDROGEN BONDS-<\/strong> are weak (compared to covalent and ionic bonds) intermolecular attractions <\/strong>that occur between polar molecules.<\/p>\n

        VANDER WAALS INTERACTIONS-<\/strong>These are temporary intermolecular attractions. (Usually, a fraction of a second.) These interactions are “created” when electrons clump on one side of an atom making that side temporarily “negative” and the other side “positive”<\/p>\n

         <\/p>\n

        STRUCTURE OF WATER AND HYDROGEN BONDING<\/strong><\/h2>\n

        Water supports life on Earth. Water makes up over 70% of the bodies of most organisms.<\/p>\n

        Water is a Polar Molecule. Because of the high electronegativity of oxygen and the low electronegativity of hydrogen, the oxygen end of the water molecule has a slight negative charge, while the hydrogen end has a slight positive charge. The water molecule’s shape is said to be “bent.” This shape means that one side of the molecule “the hydrogen side” is positive, while the other side “the oxygen side” is negative. The polar water molecules form hydrogen bonds with each other. These bonds affect many of the biologically important properties of water.<\/p>\n

        \"\"<\/p>\n

        PROPERTIES OF WATER<\/strong><\/p>\n

          \n
        • Excellent Solvent<\/strong>-Water is often referred to as the “Universal Solvent”. This means that it is great at dissolving other materials(solutes). Due to its polarity, water is best at dissolving salts and polar molecules<\/li>\n
        • Cohesion and Adhesion<\/strong>– Due to its polarity, water molecules stick to each other (cohesion) and to other polar molecules(adhesion). This property allows transpiration, the movement of water through the xylem of plants, to move water from the ground, through the plant, and eventually out into the air.<\/li>\n
        • The heat of vaporization-<\/strong> water has a high heat of vaporization and converts liquid into vapor state which is very much required for cooling off the body<\/li>\n
        • Water expands on freezing<\/strong>-Like most other compounds, the volume of water contracts as it cools down, but unlike most other materials, the volume of water begins to expand after it cools to temperatures below 4 degrees Celsius. This causes ice to be less dense than liquid water. This means that ice floats on liquid water<\/li>\n
        • High specific heat<\/strong>– Specific heat refers to the amount of heat needed to change the temperature of 1 gram of a substance by 1 degree. Water’s specific heat is very high due to the hydrogen bonds that hold the water molecules together. Due to this organism can maintain their constant body temperature.<\/li>\n<\/ul>\n

          Solved examples<\/strong><\/p>\n

          Example 1. Which of the following statements is not true?<\/strong><\/p>\n

          a. Water is polar.<\/p>\n

          b. Water stabilizes temperature.<\/p>\n

          c. Water is essential for life.<\/p>\n

          d. Water is the most abundant atom in Earth’s atmosphere.<\/p>\n

          Solution 1:<\/strong> Statement d is not true. Water is not the most abundant atom in Earth’s atmosphere—nitrogen is.<\/p>\n

           <\/p>\n

          Example 2. Julia is playing softball in the summer and begins to sweat all over. What property of water is her body relying on?<\/strong><\/p>\n

          a. The solubility of water<\/p>\n

          b. The ability of water to stabilize temperature<\/p>\n

          c. The polarity of water<\/p>\n

          d. The cohesiveness of water<\/p>\n

           <\/p>\n

          Solution 2: b.<\/strong> Water can absorb and release energy slowly. When a human sweats, the water absorbs energy and evaporates off their bodies and takes heat away with it.<\/p>\n

           <\/p>\n

          \n

          Summary <\/strong><\/p>\n

            \n
          • Water is a polar molecule because of unequal sharing of electrons between the atoms and the unsymmetrical shape of the molecule means that a water molecule has two poles – a positive charge on the hydrogen pole (side) and a negative charge on the oxygen pole (side)<\/li>\n
          • Water is a universal solvent because it is great at dissolving substances.<\/li>\n
          • Water has a high specific heat because of which it can maintain its body temperature<\/li>\n
          • Water shows the property of cohesion and adhesion so an organism is able to transport it well.<\/li>\n
          • Water has high heat of vaporization by which an organism can cool off its body.<\/li>\n
          • Water expands on freezing because of which substances become less dense and can float.<\/li>\n<\/ul>\n<\/blockquote>\n","protected":false},"excerpt":{"rendered":"

            Reference: AP Course Bio Unit 1, Chemistry of Life, Structure of water, Hydrogen bonding, Atomic structure, Vander-Waals interaction, Polarity of water,  Water properties, Cohesion and adhesion of water molecules.   Learning objectives To study previous knowledge of chemistry To understand the structure of water and bonding in it CHEMISTRY OF LIFE ATOM-The smallest unit of […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[629],"tags":[],"class_list":["post-9589","post","type-post","status-publish","format-standard","hentry","category-ap-biology"],"_links":{"self":[{"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/posts\/9589","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/comments?post=9589"}],"version-history":[{"count":0,"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/posts\/9589\/revisions"}],"wp:attachment":[{"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/media?parent=9589"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/categories?post=9589"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kapdec.com\/help\/wp-json\/wp\/v2\/tags?post=9589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}