Assertion: astatine | /r/HasProperty | estimated
Facets:
Source sentences:
text: It is estimated that the entire Earth’s crust contains only about 30 grams of astatine.
text: It is estimated that less than 30 g of astatine is present in the Earth's crust, only very few µg of astatine have been produced artificially so far, and elemental astatine has not been viewed by the naked eye due to its instability.