Assertion: seawater's concentration | /r/HasProperty | metal
Facets:
Source sentences:
text: The concentration of zinc, a metal essential to a variety of biological functions, ranges between approximately 0.05 nanomole/kg (5 × 10−11 mole/kg) in the surface ocean to as much as 6 nanomoles/kg (6 × 10−9 mole/kg) in the deep Pacific.