Water's high heat capacity is primarily attributed to the powerful hydrogen bonds that exist between its molecules.
Because of the strength of these hydrogen bonds, a significant amount of energy is required to separate them. This need for substantial energy input to break the bonds is precisely why water has a higher specific heat capacity.
In contrast, materials like sand, which are composed of metals and pyroxene (silicates that commonly contain Ca, Fe, and/or Mg), are made up of weaker covalent bonds. Less energy is needed to break these weaker bonds compared to water's strong hydrogen bonds, which explains why sand heats up and cools down much faster than water. The fundamental reason water possesses this high heat capacity property, which influences its temperature stability, lies in the unique energetic demands of its hydrogen bonding structure.
