Final answer:
The correct order of coal ranks from low to high is: lignite, bituminous, and anthracite. Lignite has the lowest energy content followed by bituminous, while anthracite has the highest energy value and is largely depleted.
Step-by-step explanation:
The correct order of ranks within the coal series, starting from low rank to high rank is: c) lignite; bituminous; anthracite.
Lignite coal, which has a high oxygen content and a hydrogen: carbon ratio of about 1.0, ranks as the lowest due to its lower heat combustion value. Following lignite in the coal series is bituminous coal. It is the most abundant in the United States and has a notable sulfur content. Bituminous coal is used in energy production and has a higher energy content compared to lignite. The highest rank is anthracite coal. With a hydrogen: carbon ratio of about 0.5 and the lowest oxygen content, anthracite has the highest heat combustion value and is the first choice for metallurgical refining.