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 astatine-210, …

Oct 16, 2024 · 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, …

astatine (At), radioactive chemical element and the heaviest member of the halogen elements, or Group 17 (VIIa) of the periodic table.

A mass spectrometer has been used to confirm that astatine behaves chemically like other halogens, particularly iodine. Astatine has no known biological role. It is toxic due to its radioactivity. Astatine …

Oct 31, 2025 · Astatine is the rarest naturally occurring element on the planet and among the least explored in the periodic table, largely because its name, derived from the Greek word for “unstable,” …

Astatine is highly radioactive and is only available in tiny quantities. Its properties are inferred from its position in the periodic table and by studying its chemistry in extremely dilute solutions. Like the other …

Apr 14, 2025 · Astatine. A radioactive halogen with the atomic symbol At, and atomic number 85. Its isotopes range in mass number from 200 to 219 and all have an extremely short half-life. Astatine …

Discover astatine's chemical properties, uses in medicine, rarity, and key facts for exams. Learn about this rare halogen's atomic number, color, and compounds.

Astatine (chemical symbol At, atomic number 85) is the rarest naturally occurring chemical element. It is a member of the halogen family of elements and is the heaviest halogen. Its chemical properties …

Astatine (At) is a rare and highly radioactive chemical element, classified as the heaviest member of the halogen group, which also includes fluorine, chlorine, bromine, and iodine. Its atomic number is 85, …