Platinum has 117 neutrons. It is element number 78, which means that it also has 78 protons and 78 electrons. Platinum's atomic weight is 195 grams per mole.
To find the number of neutrons of an element, the atomic number is subtracted from the mass number. For platinum, 195 minus 78 equals 117, which is the number of neutrons in the element.
Platinum is a dense, ductile, precious transition metal that is a member of group 10 on the periodic table. It is one of the many elements found in the Earth's crust and is considered a metal commodity due to its rarity.