Which process best describes the formation of coal as a type of matter?

• A. Coal forms from the slow decomposition of plant material under high pressure and temperature over millions of years.
• B. Coal forms from the direct precipitation of carbon dioxide from the atmosphere.
• C. Coal forms from the rapid cooling of molten rock beneath the Earth's surface.
• D. Coal forms from the crystallization of dissolved minerals in water.

Answer: (A)

Verified step by step guidance

1. Understand that coal is a type of fossil fuel formed from organic matter, specifically plant material, that has undergone physical and chemical changes over a long period.
2. Recognize that the process involves the slow decomposition of plant material, which accumulates in swampy or wet environments where oxygen is limited, slowing decay.
3. Identify that over millions of years, this plant material is buried under layers of sediment, where it is subjected to increasing pressure and temperature.
4. Know that the combination of pressure and heat causes the plant material to undergo chemical transformations, losing water and volatile compounds, and concentrating carbon content, eventually forming coal.
5. Eliminate other options by understanding that coal does not form from direct precipitation of gases, rapid cooling of molten rock, or crystallization of minerals, as these processes describe formation of other types of matter like minerals or igneous rocks.