Assertion: astatine | /r/HasProperty | unavailable
Facets:
value: essentially
type: DEGREE
value: at any one time
type: TEMPORAL
value: in nature
type: LOCATION
Source sentences:
text: Isolation: astatine is radioactive and essentially unavailable in nature.
text: Astatine is the heaviest of the halogens and is essentially unavailable in nature with less than one teaspoon of the element found in the Earth’s crust at any one time.