At
210.000Astatine
Astatin
Astatine is a very rare radioactive halogen with atomic number 85. It is known for astatine-211 targeted alpha therapy research, heavy-halogen chemistry, short-lived isotopes and trace natural occurrence in decay chains.
85
210 g/mol
[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵
2 | 8 | 18 | 32 | 18 | 7
2.2
7 g/cm³
301.9 °C
336.9 °C
Corson, MacKenzie & Segrè
Astatine was synthesized in 1940 by Dale Corson, Kenneth MacKenzie and Emilio Segrè at Berkeley by bombarding bismuth with alpha particles. Its name comes from Greek astatos, meaning unstable.
Astatine-210
Half-life: About 8.1 hours. One of the longer-lived astatine isotopes.Astatine-211
Half-life: About 7.2 hours. Alpha-emitting isotope studied for targeted alpha therapy.AtI
Astatine IodideResearch compound for comparing heavy halogen bonding and reactivity.C₆H₅At
AstatobenzeneOrganoastatine research compound for radiolabeling chemistry.- Astatine-211 targeted alpha therapy research for cancer treatment
- Heavy-halogen chemistry studies of astatide and organoastatine compounds
- Radiolabeling research for antibodies, peptides and small molecules
- Fundamental studies of relativistic effects in heavy halogens
Astatine has no natural biological role because all of its isotopes are radioactive and short-lived. Astatine-211 radiopharmaceuticals are being studied for targeted alpha therapy.
- Astatine is often described as the rarest naturally occurring element on Earth.
- All astatine isotopes are radioactive, so macroscopic chemistry is extremely difficult.
- Astatine is the heaviest halogen and can show both halogen-like and more metallic behavior.
- At-211 is attractive in nuclear medicine research because alpha particles travel only a short distance in tissue.
- Astatine has atomic number 85 and symbol At.
- Its electron configuration is [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵.
- Astatine is a radioactive halogen.
- Remember At-211 for targeted alpha therapy research and astatine for extreme natural rarity.
What is the atomic number of astatine?
The atomic number of astatine is 85.
What is the electron configuration of astatine?
Astatine has the electron configuration [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁵.
What is astatine used for?
Astatine is used mainly in research, especially At-211 targeted alpha therapy and heavy-halogen chemistry.
Why is astatine so rare?
All astatine isotopes are short-lived radioactive isotopes, so only trace amounts exist naturally in decay chains at any time.
What is astatine-211 used for?
Astatine-211 is studied as an alpha-emitting radionuclide for targeted cancer therapy.
Is astatine a halogen?
Yes. Astatine is the heaviest halogen in group 17.