Complex sentence: Astatine is the least reactive of the halogens, being less reactive than iodine; however, multiple compounds of astatine have been synthesized in microscopic amounts and studied as intensively as possible before their inevitable radioactive disintegration.
Split into simpler sentences: Astatine is the least reactive of the halogens, being less reactive than iodine. However, multiple compounds of astatine have been synthesized in microscopic amounts and studied as intensively as possible before their inevitable radioactive disintegration.