A xenon fluoride can be prepared by heating a mixture of Xe and F₂ gases to a high temperature in a pressure-proof container. Assume that xenon gas was added to a 0.25-L container until its pressure reached 0.12 atm at 0.0°C. Fluorine gas was then added until the total pressure reached 0.72 atm at 0.0°C. After the reaction was complete, the xenon was consumed completely, and the pressure of the F₂ remaining in the container was 0.36 atm at 0.0°C. What is the empirical formula of the xenon fluoride?