In a sample of water, the predominant intermolecular forces are hydrogen bonds. Hydrogen bonding is a type of dipole-dipole interaction that occurs when a hydrogen atom is covalently bonded to a highly electronegative atom such as oxygen, nitrogen, or fluorine and is attracted to another electronegative atom in a neighboring molecule.In the case of water, each water molecule H2O consists of one oxygen atom covalently bonded to two hydrogen atoms. Oxygen is more electronegative than hydrogen, which results in a partial negative charge on the oxygen atom and partial positive charges on the hydrogen atoms. The partially positive hydrogen atoms are attracted to the partially negative oxygen atoms of neighboring water molecules, forming hydrogen bonds.These hydrogen bonds contribute to the unique properties of water, including:1. High boiling and melting points: Hydrogen bonds are stronger than other types of intermolecular forces such as van der Waals forces , which means that more energy is required to break them. This results in water having a higher boiling point 100C and melting point 0C compared to other compounds with similar molecular weights.2. High heat capacity: The presence of hydrogen bonds means that water can absorb a large amount of heat energy before its temperature increases significantly. This high heat capacity allows water to act as a temperature buffer in various biological and environmental processes.3. High surface tension: The hydrogen bonds between water molecules create a strong cohesive force, leading to a high surface tension. This property allows water to form droplets and enables certain insects to "walk on water."4. Expansion upon freezing: Unlike most substances, water expands when it freezes. This is because the hydrogen bonds in ice form a hexagonal lattice structure, which is less dense than the arrangement of water molecules in the liquid state. This property causes ice to float on water, which has important implications for aquatic life in cold environments.5. Excellent solvent properties: The polar nature of water molecules allows them to interact with and dissolve a wide range of polar and ionic substances, making water an excellent solvent for many chemical reactions and biological processes.