P

Promethium

IUPAC: Promethium

Pm Elements CAS 7440-12-2
Quick Reference
Formula / NotationPm
CAS Number7440-12-2
Molecular Weight145.0
Melting Point1042.0
Boiling Point3000.0
Density7.26
SolubilitySoluble as Pm3+ salts
AppearanceSilvery, metallic, radioactive solid
Also Known AsPm, promethium element
CategoryElements

What is Promethium?

Promethium is a radioactive rare earth metal, atomic number 61. The only lanthanide with no stable isotopes. Produced in nuclear reactors. Named after the Greek Titan Prometheus. Pm-147 is the most important isotope (beta emitter).

Formula & Notation

Pm

IUPAC Name: Promethium

Other Names / Synonyms: Pm, promethium element

Properties & Characteristics

Atomic number: 61. Atomic mass: (145) g/mol. Period 6, f-block (lanthanide). Melting point: 1042 C. Boiling point: ~3000 C. Density: 7.26 g/cm3. Electronegativity: 1.13. Oxidation state: +3. No stable isotopes. Pm-147: t1/2 = 2.62 years (beta emitter).

Physical Data

PropertyValue
Melting Point1042.0
Boiling Point3000.0
Density7.26
Molecular Weight145.0
SolubilitySoluble as Pm3+ salts
AppearanceSilvery, metallic, radioactive solid

Uses & Applications

Promethium-147 nuclear batteries (pacemakers, spacecraft - historical). Luminescent paint (replaced radium). Thickness gauges and X-ray sources. Promethium-147 as beta source for research.

Safety Information

All isotopes radioactive. Pm-147: beta emitter, requires radiation shielding and handling with remote manipulation. Not found in nature in significant amounts. Requires nuclear material handling procedures and regulatory compliance.

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

Key Facts

Term Promethium
Formula Pm
CAS Number 7440-12-2
Molecular Weight 145.0
Category Elements
Synonyms Pm, promethium element

Frequently Asked Questions

Promethium is a radioactive rare earth metal, atomic number 61. The only lanthanide with no stable isotopes. Produced in nuclear reactors. Named after the Greek Titan Prometheus. Pm-147 is the most important isotope (beta emitter).

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