The various classes of coal have been exposed to high heat and pressure for different periods of time.Which of the following lists in order the classes of coal from lowest to highest energy content?
A)anthracite,bituminous,sub -bituminous,lignite
B)lignite,sub -bituminous,bituminous,anthracite
C)lignite,bituminous,sub -bituminous,anthracite
D)sub -bituminous,bituminous,lignite,anthracite
E)lignite,anthracite,sub -bituminous,bituminous

Question

Quizplus · Accepted Answer

The classes of coal from lowest to highest energy content are lignite, sub-bituminous, bituminous, and anthracite. This is because the longer a coal has been exposed to heat and pressure, the more its energy content increases. Therefore, option B is the correct order.

The Various Classes of Coal Have Been Exposed to High