The chart shows the specific heat capacities for four substances at 25°C.
Substance Specific heat (J/g°C)
air 1.020
copper 0.385
glass 0.840
iron 0.444
Javier is designing a container to hold cold items. Which substance should Javier use to best insulate the container?
A
air, because it requires a lot of energy for air to change temperatures
B
copper, because if requires very little energy for copper to change temperatures
C
glass, because it requires a lot of energy for glass to change temperatures
D
iron, because it requires a very little energy for iron to change temper
C
glass, because it requires a lot of energy for glass to change temperatures
To best insulate the container, Javier should use the substance with a high specific heat capacity. This means that the substance requires a lot of energy to change temperatures. From the given chart, the substance with the highest specific heat capacity is air with a value of 1.020 J/g°C. Therefore, Javier should use air to best insulate the container. The correct answer is A.
To determine the substance that best insulates the container, we need to consider the specific heat capacity of the substances.
Specific heat capacity is the amount of energy required to raise the temperature of a substance by 1 degree Celsius (or 1 Kelvin) per gram. A substance with a higher specific heat capacity requires more energy to change its temperature, making it a better insulator.
Looking at the given chart, we can compare the specific heat capacities of the substances:
- air: 1.020 J/g°C
- copper: 0.385 J/g°C
- glass: 0.840 J/g°C
- iron: 0.444 J/g°C
Among the given options, air has the highest specific heat capacity (1.020 J/g°C). This means it requires the most energy to change its temperature. Therefore, air is the best choice for insulating the container.
So, the correct answer is A. air, because it requires a lot of energy for air to change temperatures.