Periodic Table

Platinum

Transition Metal

Quick Facts about Platinum

Ir
  • solid- state of matter at room temperature
  • Stable- has at least one stable isotope
  • +4, +2- common oxidation states in compounds
  • FCC- crystal structure, atomic arrangement in solid form
Au

Platinum (Pt) is element 78 on the periodic table. Atomic mass of Pt: 195.0800 u. Pt is in period 6, group 10. Melting point of Pt: 2041.40 K.Density of Pt: 21.45 g/cm³.

Why Platinum Matters

The precious metal in your car's exhaust system and cancer treatment

In Your Home

  • Catalytic converters in vehicles
  • Fine jewelry and wedding rings
  • Some spark plugs

Industry Uses

AutomotiveCatalytic converters reduce harmful emissions
MedicalCisplatin chemotherapy for cancer
JewelryPremium alternative to gold and silver
ChemicalCatalyst for numerous industrial processes

In Your Body

✗ Not essential

No biological function. Platinum compounds (cisplatin) are powerful cancer drugs. Metal itself is biocompatible and inert.

Safety: Metallic platinum is non-toxic. Platinum salts can cause allergies. Cisplatin has significant side effects but saves lives.

Discovery of Platinum

Discovered by Julius Scaliger in Italy, 1735

Name origin: Spanish: platina (little silver).

History & Events

1735
European Discovery
Antonio de Ulloa reported 'platina' from South America—locals had used it for centuries
1965
Cisplatin Discovery
Barnett Rosenberg discovered platinum compounds kill cancer cells
1975
Catalytic Converter
US required catalytic converters, creating huge platinum demand

About Platinum

Dense, malleable precious metal resistant to oxidation and most acids (dissolves only in aqua regia). Six natural isotopes; Pt-190 is primordial radioactive (α, t1/2=4.9×1011 years). Cisplatin revolutionized cancer treatment—curing testicular cancer changed from a death sentence to 95%+ survival. Named 'platina' (little silver) by Spanish conquistadors who considered it a nuisance contaminating their silver. Now catalytic converters consume ~40% of production.

Atomic Properties of Pt

Atomic Number of Pt
78
Atomic Mass of Pt
195.0800 u
Electron Configuration
[Xe] 4f14 5d9 6s1
Electronegativity
2.28
Block
d-block
Group
10
Period
6

Physical Properties of Pt

Phase (STP)
solid
Melting Point of Pt
2041.40 K
Boiling Point of Pt
4098.00 K
Density of Pt
21.4500 g/cm3

Thermal Properties

Heat of Fusion
21.76 kJ/mol
Heat of Vaporization
470.00 kJ/mol
Specific Heat
0.13 J/g·K
Molar Heat Capacity
25.86 J/mol·K
Thermal Conductivity
71.60 W/m·K

Atomic Radii

Calculated
135 pm
Covalent
123 pm
Van der Waals
213 pm
Metallic
130 pm

Common Misconceptions

Wrong:Platinum is rarer than gold.
Correct:Annual production is lower, but platinum is actually slightly more abundant in Earth's crust than gold.
Wrong:Platinum jewelry is always better than gold.
Correct:Platinum is heavier and more durable, but 'better' depends on preference. Both are excellent.
Wrong:Catalytic converters contain lots of platinum.
Correct:Converters contain only 3-7 grams of platinum group metals—but that's worth $100-300.

Isotopes of Platinum

Platinum has 5 naturally occurring isotopes, plus 1 notable radioactive isotope.

IsotopeAtomic Mass (u)AbundanceHalf-LifeDecay Mode
19078Pt (Pt-190)Platinum-190 isotope189.95992970.0120%4.9×10¹¹ yearsα
19278Pt (Pt-192)Platinum-192 isotope191.96103870.7820%
19478Pt (Pt-194)Platinum-194 isotope193.962680932.86%
19578Pt (Pt-195)Platinum-195 isotope194.964791733.78%
19678Pt (Pt-196)Platinum-196 isotope195.964952125.21%
19878Pt (Pt-198)Platinum-198 isotope197.96789497.356%

Data source: NIH PubChem (aggregated from IUPAC, NIST)

Isotope Applications

Isotopes of Platinum have important real-world applications in science and industry.

Geochronology & Dating

The decay of 190Pt (with a half-life of 4.9×1011 years) to 186Os over time has been used for dating rocks and iron meteorites [527].

Medical Applications

195mPt (with a half-life of 4 days) is used for pharmacokinetic studies of platinum-based anti-tumor agents in cancer diagnosis and cancer therapy [188]. The m in the superscript of 195mPt indicates a metastable state of the isotope. 195mPt can be produced from the stable isotopes 192Os or 195Pt via the 192Os (α, n) 195mPt reaction and the 195Pt (n, n′) 195mPt reaction, respectively.

Abundance

Earth's Crust
5.00 μg/kg

Uses

Used in jewelry, to make crucible and special containers and as a catalyst. Used with cobalt to produce very strong magnets. Also to make standard weights and measures. Resists corrosion and acid attacks except aqua regia.

Sources

Produced from deposits of native, or elemental, platinum.

Geochemistry

Goldschmidt
siderophile
Geochemical Class
noble metal

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