Explain how the hydrogen bonding between water molecules is responsible for the high specific heat capacity of water, and outline the significance of this property for aquatic organisms.

Water molecules form hydrogen bonds with neighbouring molecules because the oxygen atom carries a partial negative charge (δ−) and the hydrogen atoms a partial positive charge (δ+). These bonds are strong and numerous in liquid water. To increase the temperature of water, a large amount of heat energy must first break many of these hydrogen bonds; only after they are broken does the kinetic energy of the molecules rise, so a high specific heat capacity results. Consequently, water resists rapid temperature changes and keeps aquatic habitats thermally stable. This thermal stability is crucial for aquatic organisms because their enzymes, metabolic reactions and homeostatic mechanisms operate optimally only within a narrow temperature range.