0 a chemical element that is radioactive and is the rarest natural element on the Earth's surface:
The properties of astatine remain a mystery.
The lowest element in this group is also a highly radioactive and rare element, astatine.
Fluorine and astatine are halogens.
What is the physical state of astatine at room temperature?
She discovered that the element 85 astatine is a product of the natural decay processes.
Accordingly, much less is known about astatine than most other elements.
Four out of these isotopes (astatine-215, astatine-217, astatine-218, and astatine-219) are found due to their production in major natural decay chains.
The least stable ground state isotope is astatine-213, with a half-life of 125 nanoseconds.
Even though heavier astatine isotopes release less energy, no long-lived astatine isotope exists, due to the increasing role of beta decay (electron emission).