Rhodium (Rh)

Rhodium is a rare, silvery-white, hard, corrosion-resistant transition metal.

Core Principles & Analysis

• William Hyde Wollaston discovered rhodium in 1803, naming it from the Greek for rose after the color of its salts.
• It is exceptionally reflective and corrosion resistant, and it has frequently traded as the most expensive precious metal.
• Its dominant use is in three-way catalytic converters, where it reduces nitrogen oxides in vehicle exhaust.

Specifications & Metrics

• NUM: 45
• SYMBOL: Rh
• CATEGORY: Transition Metal
• ATOMIC MASS: 102.9055 u
• ELECTRONEGATIVITY: 2.28 Pauling
• ATOMIC RADIUS: 195 pm
• IONIZATION ENERGY: 7.459 eV
• ELECTRON AFFINITY: 1.137 eV
• MELTING POINT: 2237 K
• BOILING POINT: 3968 K
• DENSITY: 12.4 g/cm³
• ELECTRON CONFIGURATION: [Kr]5s1 4d8
• OXIDATION STATES: +3
• STANDARD STATE: Solid
• GROUP BLOCK: Transition metal
• YEAR DISCOVERED: 1803