Why can water absorb a great amount of heat with little increase in its temperature? What is this property called?

Hydrogen bonds are remarkably influential when it comes to determining the properties of water. A hydrogen bond is a weak bond formed when a hydrogen atom, covalently attached to a highly electronegative atom such as oxygen, is attracted to another electronegative atom. In water, each molecule forms hydrogen bonds with its neighbors, resulting in a structured network.

These bonds are not as strong as covalent bonds but are stronger than van der Waals forces, which means they're significant enough to affect water's physical properties but weak enough to be broken at moderate temperatures. It requires a considerable amount of energy to disrupt these bonds, hence when heat is applied to water, much of this energy is used in overcoming the attraction between the molecules rather than increasing the kinetic energy, which would raise the temperature. This characteristic is fundamental to water's role as a buffer against rapid temperature changes, which is vital for all forms of life on Earth.

Temperature regulation is a key aspect of both environmental science and biological systems. The high specific heat capacity of water makes it an excellent regulator of temperature, which is why large bodies of water like oceans and lakes have a stabilizing effect on the climate of surrounding areas.

This trait is due to the heat absorption and release process involving the breaking and forming of hydrogen bonds. Energy spent in breaking hydrogen bonds as water warms up is released when the water cools, and the bonds re-form. Consequently, this process prevents extreme changes in temperatures, protecting organisms and ecosystems from the potentially harmful effects of rapid temperature fluctuations. It also explains why coastal regions typically have milder climates and experience less dramatic temperature changes compared to interior continental areas.

Heat absorption is a critical concept that directly relates to the high specific heat capacity of water. When heat is absorbed by water, a large fraction of that energy goes into breaking the hydrogen bonds, which is why water's temperature doesn't rise as rapidly as in substances with weaker intermolecular forces.

The fact that water can absorb a large amount of heat makes it an effective coolant and a key component in many thermoregulatory processes, such as the human body's maintenance of constant internal temperature. Moreover, the global climate is significantly influenced by water's capacity to absorb and store heat. Solar heat absorbed by the oceans is gradually released over time, moderating the earth's climate and influencing weather patterns. Without the high heat absorption capability of water, earth's environmental and biological systems would be much less resilient to the energy fluctuations that occur naturally and due to human activity.