Question

a solid halogen


Please answer fast

Answer 1

Iodine is a chemical element with symbol Iand atomic number 53. The heaviest of the stable halogens, it exists as a lustrous, purple-black metallic solid at standard conditionsthat sublimes readily to form a violet gas. The elemental form was discovered by the French chemist Bernard Courtois in 1811. It was named two years later by Joseph-Louis Gay-Lussac from this property, after the Greekἰωδης "violet-coloured". Astatine is a radioactive chemical elementwith 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 astatine-210, with a half-life of 8.1 hours. A sample of the pure element has never been assembled, because any macroscopic specimen would be immediately vaporized by the heat of its own