Liquid the distances between the molecules become smaller. When the liquid reaches its freezing point the molecules will usually lock into a very specific order, called crystallizing, and the bonds between them become more rigid, changing the liquid into its solid state (unless supercooling occurs). Only two elements are liquid at standard conditions for temperature and pressure: mercury and bromine. Four more elements have melting points slightly above room temperature: francium, caesium, gallium and rubidium. Metal alloys that are liquid at room temperature include NaK, a sodium-potassium metal alloy, galinstan, a fusible alloy liquid, and some amalgams (alloys involving mercury). Pure
Liquid metal ion source allowed to flow to the apex of a sharp needle. Most focused ion beam instruments use a liquid-metal ion sources (LMIS) often with gallium. In a gallium LMIS, gallium metal is placed in contact with a tungsten needle and heated gallium wets the tungsten and flows to the tip of the needle where the opposing forces of surface tension and electric field produce the cusp shaped Taylor cone. The tip radius of this cone is ~2 nm. The electric field at this small tip is typically greater than 1 x 10 V/cm and causes ionization and field emission of the