Question

the decomposition of plants plays an important role in the carbon cycle. three hundred million years ago, many parts of earth were covered by warm, swamp - like forests. when the trees, ferns, and other plants in these forests died, many were buried under layers of mud, water, rock, and sand. over hundreds of thousands of years, pressure and heat transformed carbon - based molecules in these dead plants into a fossil fuel called coal. which of the following statements are true? select all that apply. coal contains the carbon that was once part of ancient plants. the formation of coal takes hundreds of thousands of years. coal forms when plants decompose on earth’s surface. carbon can be stored deep underground as coal.

Explanation:

• "Coal contains the carbon that was once part of ancient plants": The text says pressure and heat transformed carbon - based molecules in dead plants into coal. So, the carbon in coal was from ancient plants.
• "The formation of coal takes hundreds of thousands of years": The text states "Over hundreds of thousands of years...into a fossil fuel called coal".
• "Carbon can be stored deep underground as coal": The dead plants were buried under layers of mud, water, rock, and sand and then became coal, which implies carbon storage underground as coal.
• "Coal forms when plants decompose on Earth's surface": The text says plants were buried under layers (not just decomposing on the surface) before forming coal. So this statement is false.

Answer:

• Coal contains the carbon that was once part of ancient plants.
• The formation of coal takes hundreds of thousands of years.
• Carbon can be stored deep underground as coal.