Astatine sublimes less readily than does iodine, having a lower vapor pressure.[8] Even so, half of a given quantity of astatine will vaporize in approximately an hour if put on a clean glass surface at room temperature.[a] The absorption spectrum of astatine in the middle ultraviolet region...
Astatine is a nonmetal halogen with an unknown appearance. It is speculated that astatine would be a black lustrous solid at room temperature. It is also speculated that this element can act as a semiconductor and that it has some metallic characteristics. This is why it is often categorized ...
Color/appearanceGrayish black[3] LusterMetallic[3] OdorUnknown[3] Melting point/freezing point300°C (572°F)[1] Boiling point350°C (662°F)[1] DensityUnknown[1] State at room temperature (25°C) (solid/liquid/gas)Solid [1]