Gallium has a melting point of 30 °C, which is low enough that body heat alone can melt it. The element's melting point can be lowered further by dissolving other metals to form gallium-based alloys—such as eutectic gallium indium (EGaIn)—which are liquid at room temperature. Those alloys are referred to as liquid metals, or simply LMs. (See the article by Michael Dickey, Physics Today, April 2021, page 30.)
LMs are similar to water in some respects. For example, both water and EGaIn have similar viscosities, of 2.0 mPa·s and 1.0 mPa·s, respectively. They also both expand when they freeze. But water boils at 100 °C and has a vapor pressure of 2.33 kPa, whereas gallium boils at 2400 °C and has an extremely low vapor pressure, which practically eliminates inhalation concerns during its handling or processing. Additionally, EGaIn has metallic thermal and electrical conductivities that are orders of...