Assertion: astatine | /r/AtLocation | only vanishingly small amounts
Facets:
value: in nature
type: LOCATION
value: vanishingly
type: DEGREE
Source sentences:
text: Astatine is found in only vanishingly small amounts in nature—it is believed that only 30 grams (1 ounce) of the element are present in Earth's crust at any one time.