An automobile engine is about 20 to 30% efficient in converting chemical energy to mechanical energy. Cells are about 39% efficient in the transformation of glucose to ATP. The rest of the energy is lost as heat. This is illustrative of the

Second Law of Thermodynamics

Explanation:

The Second Law of Thermodynamics states that the entropy, which can be defined as the state of disorder in a given system, will always increase across time. This Law poses that the processes of energy transfer, as well as those involving energy transformation, increase the entropy of the universe. As a predictable consequence, the Second Law of Thermodynamics also states that organisms (which represent thermodynamically closed systems) are in a continuous battle against the constant increase in the entropy of the universe, where energy is essentially lost in the form of heat.

i think the answer is

mass

a fossil fuel is a fuel formed by natural processes, such as anaerobic decomposition of buried dead organisms, containing energy originating in ancient photosynthesis.[1] the age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years.[2] fossil fuels contain high percentages of carbon and include petroleum, coal, and natural gas.[3] other commonly used derivatives include kerosene and propane. fossil fuels range from volatile materials with low carbon to hydrogen ratios like methane, to liquids like petroleum, to nonvolatile materials composed of almost pure carbon, like anthracite coal. methane can be found in hydrocarbon fields either alone, associated with oil, or in the form of methane clathrates.

the theory 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 was first introduced by andreas libavius "in his 1597 alchemia [alchymia]" and later by mikhail lomonosov "as early as 1757 and certainly by 1763".[4] the first use of the term "fossil fuel" was by the german chemist caspar neumann, in english translation in 1759.[5]

in 2017 the world's primary energy sources consisted of petroleum (34%), coal (28%), natural gas (23%), amounting to an 85% share for fossil fuels in primary energy consumption in the world.[6] non-fossil sources in 2006 included nuclear (8.5%), hydroelectric (6.3%), and others (geothermal, solar, tidal, wind, wood, waste) amounting to 0.9%.[7] world energy consumption was growing at about 2.3% per year. in 2015 about 18% of worldwide consumption was from renewable sources.[8]