Mercury is used in lab thermometers. At r.t.p., which state of matter does it exist in?
Mercury exists as a liquid at room temperature. It, and bromine, are the only two elements that are liquids at room temperature.
Mercury's vapor pressure is very low (1.2 micrometers)at room temperature so practically speaking there is no vapor phase above the liquid.
At normal room temperature and pressure (r.t.p.) mercury exists in liquid state. Mercury melts at 38.87 degrees C and boils at 356.58 degrees C. This very high melting and boiling point makes mercury a very suitable material for use in laboratory and clinical thermometers.
Thermometers for measuring temperatures substantially below freezing point of mercury often use alcohol.