what is the rarest substance on Earth
Answer (1)
The rarest naturally occurring substance on Earth is the element Astatine (At).It's not rare like gold; it's rare because it is incredibly unstable and radioactive. Its most stable form has a half-life of only 8.1 hours, meaning it decays almost as soon as it's formed.Scientists estimate there is less than one gram of Astatine present on the entire planet at any given moment.What about other contenders?Francium (Fr) - This is the second-rarest naturally occurring element, right behind Astatine. It is also extremely radioactive, with its most stable isotope having a half-life of only 22 minutes. There are only a few grams of it on Earth at any time.Antimatter - If you consider "substance" in a broader sense, antimatter is arguably the rarest. While tiny amounts are produced in labs (like CERN) and occur in natural phenomena (like lightning), it is annihilated instantly upon contact with regular matter. The amount of antimatter existing freely on Earth is essentially zero.Man-made Elements (e.g., Oganesson) - Elements heavier than uranium on the periodic table are artificially created in particle accelerators. They are incredibly rare because they only exist for fractions of a second in a lab before decaying. However, they are not considered "naturally occurring" substances on Earth.
