Platinum is a chemical element, having the chemical symbol Pt. Its atomic number (the number of protons) is 78. It has a standard atomic weight of 195.078 g•mol −1 and is a solid in its elemental form.
Platinum is considered a member of the "Transition metal" class of elements. At a pressure of 101.325 kPa, it has a boiling point of 3,825 °C and a melting point of 1,768.4 °C. Platinum is also considered a precious metal and is used as a catalyst in many chemical reactions.