Nonetheless, 0° C is not the coldest possible temperature. In some parts of the United States, days or weeks may go by in winter when the temperature never rises
above 0° C. Therefore, 0° C is also not the coldest possible temperature. However, there is a coldest possible temperature on both the Fahrenheit and Celsius scales, called absolute zero.*
*Absolute zero on the Fahrenheit scale is -459 degrees.
Determining Absolute Zero
Suppose an experiment is done to determine if there is a lowest possible temperature. Helium gas is put in a cylinder with a pressure gauge. Helium is chosen because the atoms are very small and the attractive forces between helium atoms are also very small. A gas whose atoms exert no forces on each other and whose atoms have no volume is called an "ideal gas." Ideal gases do not exist, but helium behaves like an ideal gas if the temperature is relatively high (room temperature) and the pressure is low (atmospheric pressure).
The cylinder and gas have an initial temperature of 25° C. The cylinder is placed in a refrigerator and the temperature in the refrigerator is lowered to 15° C.
This is a free page. This page contains 191 words. This
article contains 1,650 words (approx. 6 pages at 300
words per page).
Read the rest of this Article with our Absolute Zero Access Pass.
