Coal is categorized into three major types based on carbon content and grade: lignite, bituminous, and anthracite. Which set lists these correctly?

Coal is categorized into three major types based on carbon content and grade: lignite, bituminous, and anthracite. Which set lists these correctly?

• A. Lignite, Bituminous, Anthracite
• B. Lignite, Bituminous, Subbituminous
• C. Peat, Lignite, Charcoal
• D. Anthracite, Subbituminous, Peat

Answer: (A)

Coal is classified by how mature it is and its carbon content, typically arranged from lower to higher carbon content as lignite, bituminous, then anthracite. Lignite, often called brown coal, has the least carbon and the most moisture, so it yields less energy. Bituminous coal sits in the middle with a higher carbon content and is widely used because it provides a good balance of energy and workability. Anthracite has the highest carbon content, burns the hottest and cleanest, and is the most mature form. The set that lists these three in that order matches this progression of increasing carbon content and energy, making it the correct choice. The other options bring in peat, subbituminous coal, or charcoal, which are not part of the three major categories described by carbon content in this context.

Coal is classified by how mature it is and its carbon content, typically arranged from lower to higher carbon content as lignite, bituminous, then anthracite. Lignite, often called brown coal, has the least carbon and the most moisture, so it yields less energy. Bituminous coal sits in the middle with a higher carbon content and is widely used because it provides a good balance of energy and workability. Anthracite has the highest carbon content, burns the hottest and cleanest, and is the most mature form.

The set that lists these three in that order matches this progression of increasing carbon content and energy, making it the correct choice. The other options bring in peat, subbituminous coal, or charcoal, which are not part of the three major categories described by carbon content in this context.