Astatine is a chemical element; it has symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth's crust, occurring only as the decay product of various heavier elements. All of astatine's isotopes are short-lived; the most stable is …

2024年10月16日 · Astatine (At) is a rare and highly radioactive element with atomic number 85. It is part of the halogen group (Group 17) in the periodic table, which also includes fluorine, chlorine, bromine, and iodine. Unlike the other halogens, astatine has no stable isotopes.

2025年4月4日 · Astatine (At), radioactive chemical element and the heaviest member of the halogen elements, or Group 17 (VIIa) of the periodic table. Astatine, which has no stable isotopes, was first synthetically produced (1940) at the University of California by American physicists Dale R. Corson, Kenneth R.

2017年5月24日 · Astatine is the rarest element on Earth; only approximately 25 grams occur naturally on the planet at any given time. Its existence was predicted in the 1800s, but was finally discovered about 70...

Astatine is a shiny dark colored element. Astatine is a radioactive element. It is a semiconductor and can have metallic properties. Astatine undergoes sublimation but less readily than iodine and have a low vapor pressure.

Element Astatine (At), Group 17, Atomic Number 85, p-block, Mass [210]. Sources, facts, uses, scarcity (SRI), podcasts, alchemical symbols, videos and images.

2025年1月22日 · Astatine is the rarest naturally occurring element in the Earth's crust with less than 25 grams present on the entire planet at any given time. Astatine is so rare that scientists still don't know basic information about the element, like what it looks like.

What is Astatine? Astatine is the 85th element of the periodic table with a symbol ‘At’. It is a radioactive element and is said to be the most heavier among the halogens. This element exhibits similar chemical properties that of the element iodine.

The heavy halogen, astatine-211 is one of the prominent α-particle-emitting radionuclides in practice. Being a halogen, it can often be incorporated into biomolecules of interest by adapting radioiodination chemistry.

2025年3月19日 · Astatine-211’s ability to form chemical bonds helps keep it more stable than metal-based radionuclides. This makes it an ideal candidate for treating glioblastomas and other brain tumors. The production of astatine-211 starts with bismuth-209, an abundant element found in everyday products like Pepto-Bismol. Unlike other radionuclides that ...