Question

Which are fossil fuels? How were coal and petroleum formed?

Answer 1

Hint: To answer this question we should recall the definition of fossil fuels, and their origin. And to answer the second half of question, we should recall that coal is found in terrestrial areas and petroleum is found in aquatic conditions.

Step by step answer:
So first we will know about fossil fuels. In the term “fossil fuels”, fossil means “obtained by digging, found buried in the earth”.
We should know that fossil fuels formed from the fossilized remains of dead plants by exposure to heat and pressure in the Earth's crust over millions of years. A fossil is any preserved remains, impression, or trace of any once-living thing from a past geological age.
So from above definition we can say that, if we are talking about millions of years ago. Plants and animals which are dead and buried in earth’s crust. Their dead remains got exposed to heat and pressure by nature. And with the passage of time like millions of years later, when we dig up the earth crust we found dead remains of plants and animals in the form of coal. This was about terrestrial conditions.
In aquatic life there are phytoplankton and zooplankton. We should know that Phytoplankton are aquatic plants; Zooplankton are small aquatic animals. Phytoplankton depends on sunlight for making their food; they primarily live on the surface of the water, while zooplankton lives in the darker and colder area of the water body. Similarly as in the case of coal, millions of years ago dead remains of phytoplankton and zooplankton got buried in an aquatic bed. With the continued impact of pressure and with no oxygen like conditions they started to perform anaerobic reactions. This whole process leads to formation of petroleum.
We should know that there is a wide range of organic compounds in any given fuel. The specific mixture of hydrocarbons gives a fuel its characteristic properties, such as density, viscosity, boiling point, melting point, etc. Some fuels like natural gas, for instance, contain only very low boiling, gaseous components. Others such as gasoline or diesel contain much higher boiling components.
We should know that fossil fuels are of great importance because they can be burned (oxidized to carbon dioxide and water), producing significant amounts of energy per unit mass. Coal was used to run furnaces for the smelting of metal ore. Natural gas deposits are also the main source of helium.
Examples of fossil fuels: Coal, oil, and natural gas are examples of fossil fuels that we should remember. We should know that coal is usually found in sedimentary rock deposits where rock and dead plant and animal matter are piled up in layers. It is interesting to know that more than 50 % of a piece of coal’s weight must be from fossilized plants. Oil is originally found as a solid material between layers of sedimentary rock, like shale. This material is heated in order to produce the thick oil that can be used to make gasoline. Natural gas is usually found in pockets above oil deposits. It can also be found in sedimentary rock layers that don’t contain oil. Natural gas is primarily made up of methane.

Note: We know that all fossil fuels are non-renewable sources of energy. So at some point of time they will be drained up completely. The main alternatives to oil and gas energy include nuclear power, solar power, ethanol, and wind power. It is interesting to know that the government currently provides a lot of subsidies for consumers who choose cleaner forms of renewable energy either for their house or for their vehicles. We should note that nuclear power is the most effective substitute to challenge fossil fuels for future energy consumption. Compared to coal, gas, oil, and ethanol, nuclear power produces almost negligible adverse climate effects. More importantly, nuclear power can run much more cheaply than other clean energy forms, such as solar, wind, or hydropower.