Thermal Properties of Water

Specific Heat Capacity: The thermal inertia of a substance—its resistance to a change in temperature.

It's the amount of heat required to change the temperature of $1 \text{ gram}$ of the substance

by $1^\circ\text{C}$. Water has a very high specific heat capacity.Thermal Expansion: Most

substances expand when heated and contract when cooled, due to increased molecular motion.

Water is a notable exception: it is densest at $4^\circ\text{C}$ and expands when cooled further (which

is why ice floats).