Which example best describes both an elemental pool where an element accumulates and an elemental sink where it is removed from circulation and locked up for long periods?
A) Calcium in bones,which remains fairly stable throughout an animal's life
B) Nitrogen that is made available to plants from their bacterial endosymbionts
C) Fossil fuel deposits in which carbon is stored for hundreds of millions of years
D) Atmospheric oxygen levels,which are maintained stable by photosynthesis
E) Sulfur compounds,which react with water to produce acid precipitation

Question

Quizplus · Accepted Answer

Fossil fuel deposits, such as coal, oil, and natural gas, act as both an elemental pool and sink for carbon. Carbon accumulates in these deposits over millions of years and is removed from circulation until it is burned or otherwise released into the atmosphere.

Which Example Best Describes Both an Elemental Pool Where an Element