what metal is liquid at room temperature 4 stars?, At room temperature mercury (Hg) is the only liquid metal. Mercury is a heavy metal that freezes at about -39 degrees Celsius and boils at about 356 degrees Celsius. Because mercury is liquid at room temperature, it is used in a variety of applications such as barometers, thermometers, and some electrical circuits. However, it is important to handle mercury carefully as it is toxic to humans and the environment.