Platinum, symbolized as Pt, is a rare and dense precious metal known for its resistance to corrosion and high melting point. This silvery-white transition metal is valued in jewelry, electronics, and catalytic converters across various industries. Like all elements, platinum is composed of atoms, and the specific composition of its nucleus determines its properties. To answer the question of the neutron count in its most common version, we must delve into the fundamental structure of the platinum atom and its various natural forms.
Platinum’s Foundational Atomic Identity
The identity of platinum is fixed by its atomic number, which is 78. This number represents the exact count of protons found within the nucleus of every single platinum atom. The number of protons is the defining characteristic of an element, distinguishing platinum from its neighboring elements on the periodic table, iridium (77 protons) and gold (79 protons).
The atomic number establishes the first piece of information necessary for determining the neutron count. All atoms of platinum must contain exactly 78 protons. This constant proton count gives platinum its chemical properties and places it in Group 10 of the periodic table.
Identifying Platinum’s Most Common Isotope
While the proton count remains constant, the number of neutrons can vary, leading to different forms of the element known as isotopes. Isotopes are atoms of the same element that have differing mass numbers due to a variation in their neutron count. Platinum naturally exists as a mixture of six isotopes in varying abundances.
These naturally occurring versions include Platinum-192, Platinum-194, Platinum-195, Platinum-196, and Platinum-198, along with a trace amount of Platinum-190. The mass number (e.g., 195 in Platinum-195) represents the total number of particles—protons plus neutrons—in the nucleus. Among all these versions, Platinum-195 is the most abundant, making up approximately 33.8% of all naturally occurring platinum atoms.
Calculating the Neutron Count
To determine the number of neutrons in the most common version of platinum, Platinum-195, a simple calculation is required. The mass number (A) is the sum of the protons (the atomic number, Z) and the neutrons (N), which can be expressed by the formula: N = A – Z.
We use the mass number of the most common isotope, 195, and the fixed atomic number of platinum, 78. The calculation is performed by subtracting the number of protons from the mass number: 195 – 78 = 117. This result shows that the most abundant version of platinum, Platinum-195, contains 117 neutrons in its nucleus.