A device used to perform this process by running a current through a titanium filament may become less effective due to the presence of inert gases like methane. Measuring this process allows calculation of vapor pressure with a Knudsen cell. Using a vacuum speeds up the rate of this process during lyophilization. The energy for ionization and this process quantifies a metal’s enthalpy in a (*) Born-Haber cycle. Heat transfer coefficients of convection can be determined by measuring this process in balls of naphthalene. Compounds purified by this process collect on a cold finger. The heat of this process equals heat of fusion plus heat of vaporization. Dry ice undergoes this process at room (10[1])temperature. For 10 points, name this phase transition of a solid into a gas. ■END■