C

Chromium

IUPAC: Chromium

Cr Elements CAS 7440-47-3
Quick Reference
Formula / NotationCr
CAS Number7440-47-3
Molecular Weight52.0
Melting Point1907.0
Boiling Point2671.0
Density7.15
SolubilityInsoluble in water
AppearanceHard, lustrous, steel-grey metal
Also Known AsCr, chromium metal
CategoryElements

What is Chromium?

Chromium is a hard, lustrous transition metal, atomic number 24. Famous for its corrosion resistance and bright finish in electroplating. Chromium(III) compounds are relatively safe but chromium(VI) compounds are highly toxic and carcinogenic. The most important steel alloy component (stainless steel).

Formula & Notation

Cr

IUPAC Name: Chromium

Other Names / Synonyms: Cr, chromium metal

Properties & Characteristics

Atomic number: 24. Atomic mass: 51.996 g/mol. Period 4, Group 6. Melting point: 1907 C. Boiling point: 2671 C. Density: 7.15 g/cm3. Electronegativity: 1.66. Oxidation states: 0, +2, +3, +6. [Ar]3d54s1 config (half-filled d stability). Four stable isotopes.

Physical Data

PropertyValue
Melting Point1907.0
Boiling Point2671.0
Density7.15
Molecular Weight52.0
SolubilityInsoluble in water
AppearanceHard, lustrous, steel-grey metal

Uses & Applications

Stainless steel (Cr gives corrosion resistance). Chrome plating. Chromite refractory bricks. Cr2O3 pigment (green). Tanning of leather (Cr(III) salts). Catalysts. Ruby (Cr3+ in Al2O3). Chromate corrosion inhibitors.

Safety Information

Cr(VI) (hexavalent chromium): highly toxic carcinogen (IARC Group 1), causes lung cancer, dermal ulcers, eye damage. OSHA PEL: 0.005 mg/m3. Cr(III): much less toxic. Chrome plating baths: serious inhalation hazard. Strict regulatory controls for Cr(VI).

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

Key Facts

Term Chromium
Formula Cr
CAS Number 7440-47-3
Molecular Weight 52.0
Category Elements
Synonyms Cr, chromium metal

Frequently Asked Questions

Chromium is a hard, lustrous transition metal, atomic number 24. Famous for its corrosion resistance and bright finish in electroplating. Chromium(III) compounds are relatively safe but chromium(VI) compounds are highly toxic and carcinogenic. The most important steel alloy component (stainless steel).

More "C" Terms

View all "C" terms →
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z