Absolute zero is the temperature at which
- A. the volume of an ideal gas extrapolates to zero
- B. water freezes
- C. all gases liquefy
- D. pressure becomes infinite
Explanation
Extending the straight line of a volume against temperature graph backwards, it meets the axis at minus 273.15 degrees Celsius, which is defined as zero kelvin. No real gas actually reaches this point, since every gas liquefies first, so the zero volume is an extrapolation rather than an observation. It is the lowest temperature theoretically attainable.