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Astatine

IUPAC: Astatine

At Elements CAS 7440-68-8
Quick Reference
Formula / NotationAt
CAS Number7440-68-8
Molecular Weight210.0
Melting Point302.0
Boiling Point337.0
Density7.0
SolubilityUnknown (estimated)
AppearanceBelieved to be metallic or metalloid solid; radioactive
Also Known AsAt, astatine element
CategoryElements

What is Astatine?

Astatine is a radioactive halogen, atomic number 85. The rarest naturally occurring element in Earth crust (total amount ~31 grams at any time). All isotopes are short-lived. At-211 is being investigated for targeted alpha therapy in cancer treatment.

Formula & Notation

At

IUPAC Name: Astatine

Other Names / Synonyms: At, astatine element

Properties & Characteristics

Atomic number: 85. Atomic mass: (210) g/mol. Period 6, Group 17 (halogen). No stable isotopes. At-210: t1/2 = 8.1 h. At-211: t1/2 = 7.2 h (alpha emitter). Estimated melting point: 302 C. Properties inferred from periodic trends. Expected to be metallic solid.

Physical Data

PropertyValue
Melting Point302.0
Boiling Point337.0
Density7.0
Molecular Weight210.0
SolubilityUnknown (estimated)
AppearanceBelieved to be metallic or metalloid solid; radioactive

Uses & Applications

At-211 targeted alpha radiotherapy (cancer treatment - labelled antibodies and peptides). Research into astatine chemistry. Production in cyclotrons from bismuth targets. At-211 in thyroid cancer treatment trials.

Safety Information

Extremely radioactive - all isotopes short-lived. Production only in microgram quantities in particle accelerators. Alpha emitter - internal contamination extremely hazardous. Handle with microchemical techniques and appropriate radiation shielding.

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

Key Facts

Term Astatine
Formula At
CAS Number 7440-68-8
Molecular Weight 210.0
Category Elements
Synonyms At, astatine element

Frequently Asked Questions

Astatine is a radioactive halogen, atomic number 85. The rarest naturally occurring element in Earth crust (total amount ~31 grams at any time). All isotopes are short-lived. At-211 is being investigated for targeted alpha therapy in cancer treatment.

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