A water molecule H2O consists of two hydrogen atoms bonded to a single oxygen atom. The molecular structure of water is bent or V-shaped, with an angle of approximately 104.5 degrees between the hydrogen-oxygen-hydrogen atoms. This bent structure is a result of the oxygen atom having two lone pairs of electrons, which occupy more space than the bonding pairs, causing the molecule to adopt this shape.In a water molecule, the bonding between the hydrogen and oxygen atoms is covalent, meaning that the atoms share electrons. However, the oxygen atom is more electronegative than the hydrogen atoms, meaning it has a greater ability to attract the shared electrons. As a result, the electrons spend more time around the oxygen atom, creating a partial negative charge - on the oxygen and partial positive charges + on the hydrogen atoms. This uneven distribution of electron density leads to the molecule being polar, with a net dipole moment.The polarity of water molecules contributes to their ability to form hydrogen bonds with other molecules. A hydrogen bond is a relatively strong intermolecular force that occurs between a hydrogen atom with a partial positive charge + and an electronegative atom such as oxygen, nitrogen, or fluorine with a partial negative charge - on another molecule. In the case of water, the partially positive hydrogen atoms can form hydrogen bonds with the partially negative oxygen atoms of neighboring water molecules.The hydrogen bonding in water molecules leads to several unique properties, including:1. High boiling and melting points: The hydrogen bonds between water molecules require a significant amount of energy to break, leading to higher boiling and melting points compared to other molecules of similar size and weight.2. High heat capacity: Water can absorb a large amount of heat before its temperature increases significantly, making it an excellent coolant and temperature regulator in various biological and environmental processes.3. High surface tension: The hydrogen bonding between water molecules at the surface creates a strong cohesive force, leading to a high surface tension that allows certain insects to walk on water and causes water droplets to form beads.4. Excellent solvent properties: The polarity of water molecules allows them to interact with and dissolve a wide range of polar and ionic compounds, making water an excellent solvent for many substances.5. Ice's lower density than liquid water: When water freezes, the hydrogen bonds form a hexagonal lattice structure, which occupies more space than the liquid state, causing ice to be less dense than liquid water. This property is crucial for aquatic life, as it allows ice to float on the surface of bodies of water, insulating the water below and preventing it from freezing solid.