If, as a pioneer, you wished to warm your room by taking an object heated on top of a pot-bellied stove to it, which of the following 15-pound objects, each heated to 100 degree C, would be the best choice? The specific heat capacity (in J/g- degree C) for each substance is given in parentheses. Iron (0.450), copper (0.387), granite (0.79), gold (0.129), water (4.184).
a. iron
b. copper
c. granite
d. gold
e. H2O

The specific heat capacity is defined as the amount of heat required to raise the temperature of the substance in 1 unit. If you have to warm your room, you have to choose the substance with the highest specific heat capacity value. This substance will retain the highest amount of heat. From the options, the highest value is 4.184 J/g°C (water, H₂O). Thus, 1 gram of water will retain 4.184 J when the temperature is raised to 1°C. That is a higher amount of heat in comparison with, for example, granite, which is able to retain 0.79 J per gram when the temperature is raised to 1°C.

However, you have to consider that the boiling point of water is 100°C, so the temperature at which you have to warm the room is the temperature at which water will be passing to the gas state.