Which of the following accounts for why nitrous oxide E cylinders have to be weighed to determine the amount of N2O that is remaining?
A. N2O is a liquid at normal room temperature and barometric pressure.
B. N2O exists as both a gas and a liquid at room temperature and barometric pressure.
C. N2O's critical temperature is below room temperature.
D. N2O's critical temperature is above room temperature.
E. N2O has a high vapor pressure.