Learning goal 3: Choose one of the three fossil fuels – coal, oil or natural gas – and describe:how it was formedhow we use it as a source of energy

Sure, I will choose oil as the fossil fuel for this discussion.

1. Formation of Oil: Oil is formed from the remains of tiny plants and animals (plankton) that died in ancient seas between 10 million and 600 million years ago. After the organisms died, they sank into the sand and mud at the bottom of the sea. Over millions of years, the remains were covered by layers of mud and sand, which turned into rock due to the pressure from the layers above. The pressure and the intense heat at those depths transformed the remains into oil and gas. Over time, some of this oil and gas began to move upward through the earth's crust until they were trapped beneath impermeable rocks, forming an oil reservoir.

2. Use of Oil as a Source of Energy: Oil is a major source of energy due to its high energy density, transportability, and relative abundance. It is refined into various fuels including gasoline, diesel, and jet fuel. These fuels are used in vehicles, airplanes, and ships, making oil crucial for transportation. Oil is also used in power plants to generate electricity. In addition to fuels, oil is used to produce a variety of products including plastics, synthetic materials, and chemicals. Despite its many uses, burning oil releases carbon dioxide, a greenhouse gas that contributes to climate change. Therefore, there is a growing interest in finding renewable energy sources to replace oil.

Let's choose coal as the fossil fuel to discuss.

1. Formation of Coal: Coal was formed millions of years ago, during the Carboniferous Period (known as the first coal age), when the earth was covered with swampy forests. When plants in these forests, mainly ferns and gymnosperms, died, they fell into the swampy water and began to decay. Over time, the dead plants did not completely decompose and formed a material called peat. As more and more plant material accumulated, the peat layers were subjected to heat and pressure, causing physical and chemical changes. This process, known as coalification, transformed the peat into coal over millions of years. The degree of change undergone by the coal as it matures from peat to anthracite (the hardest form of coal) is known as the rank of the coal.

2. Use of Coal as a Source of Energy: Coal is primarily used as a fuel. While it was once used to heat homes and buildings, today, coal is primarily used to generate electricity. Coal-fired power plants burn coal to produce steam, which then turns a turbine to generate electricity. Specifically, the coal is burned in a furnace where it heats water in boiler tubes to produce steam. The steam is then used to spin the turbines that generate electricity.

Coal is also used in industry, where it is burned to produce heat, and in the steel-making process, where it is used to make coke (a high-carbon fuel). Despite its widespread use, burning coal releases a significant amount of greenhouse gases, which contribute to global warming and climate change. Therefore, there is a growing push to transition away from coal and towards cleaner, renewable sources of energy.