On a hot day, a concrete sidewalk feels hotter than the water in a small swimming pool. And a sandy beach feels hotter than the lake or ocean. What do these observations tell you about temperature changes when different materials are heated?

Each type of substance or material has a different capacity to support an energy supply without raising its temperature much. Water is the substance that, when receiving energy, raises its temperature less and also when losing energy, it lowers its temperature less.

Rocks, metals, and solids in general, tend to increase the temperature greatly when receiving energy. For this reason on a hot day, the sand on the beach or the concrete sidewalk will tend to be much hotter than the water in the pool or the sea that will be warm.