Melting point of ice at 1 atmosphere of pressure is very close to ; this is also known as the ice point. In the presence of nucleating substances, the freezing point of water is not always the same as the melting point. In the absence of nucleators water can exist as a supercooled liquid down to −48.3 °C (−55 °F, 224.8 K) before freezing. The chemical element with the highest melting point is tungsten, at ; this property makes tungsten excellent for use as filaments in light bulbs. The often-cited carbon does not melt at ambient pressure but sublimes at about ;
Melting-point depression it possible to test and characterize samples with a wider distribution of particle sizes. The TEM limits the pressure range at which melting point depression can be tested. More recently, researchers developed nanocalorimeters that directly measure the enthalpy and melting temperature of nanoparticles. Nanocalorimeters provide the same data as bulk calorimeters, however additional calculations must account for the presence of the substrate supporting the particles. A narrow size distribution of nanoparticles is required since the procedure does not allow users to view the sample during the melting process. There is no way to characterize the exact size of melted particles