R

Rhodium

IUPAC: Rhodium

Rh Elements CAS 7440-16-6
Quick Reference
Formula / NotationRh
CAS Number7440-16-6
Molecular Weight102.91
Melting Point1964.0
Boiling Point3695.0
Density12.41
SolubilityInsoluble in water
AppearanceHard, lustrous, silvery-white metal
Also Known AsRh, rhodium metal
CategoryElements

What is Rhodium?

Rhodium is a hard, silvery-white platinum group metal, atomic number 45. One of the rarest and most expensive metals. Key component of catalytic converters in cars. Very high reflectivity makes it valuable for mirrors and jewellery plating.

Formula & Notation

Rh

IUPAC Name: Rhodium

Other Names / Synonyms: Rh, rhodium metal

Properties & Characteristics

Atomic number: 45. Atomic mass: 102.91 g/mol. Period 5, Group 9. Melting point: 1964 C. Boiling point: 3695 C. Density: 12.41 g/cm3. Electronegativity: 2.28. Oxidation states: +1, +3. One stable isotope: Rh-103. Platinum group metal. Highest reflectivity of any metal.

Physical Data

PropertyValue
Melting Point1964.0
Boiling Point3695.0
Density12.41
Molecular Weight102.91
SolubilityInsoluble in water
AppearanceHard, lustrous, silvery-white metal

Uses & Applications

Automotive catalytic converters (reduces NOx - most important use). Industrial catalysts (acetic acid production). Plating for jewellery and reflectors. Thermocouple alloys (Pt-Rh). Electrical contacts. High-temperature alloys.

Safety Information

Rhodium compounds: irritant to skin and eyes. Some rhodium salts reported as sensitisers. Rhodium metal: relatively low toxicity. Rh-106: radioactive fission product. Limited data on long-term exposure - handle with standard precautions.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Rhodium
Formula Rh
CAS Number 7440-16-6
Molecular Weight 102.91
Category Elements
Synonyms Rh, rhodium metal

Frequently Asked Questions

Rhodium is a hard, silvery-white platinum group metal, atomic number 45. One of the rarest and most expensive metals. Key component of catalytic converters in cars. Very high reflectivity makes it valuable for mirrors and jewellery plating.

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