Energy content of biofuel (J/kg) or equivalent units. Energy density is the amount of energy stored in a fuel per unit volume, expressed in SI units as joule per litre (J/L) or equivalent units. The table below includes entries for popular substances already used for their energy, or being discussed for such use. The second column shows specific energy, the energy content in megajoules per unit of mass in kilograms, useful in understanding the energy that can be extracted from the fuel. The third column in the table lists energy density, the energy content per liter of volume, which is useful for understanding the
Scientific law water); although in many systems (notably biomacromolecules and minerals) the ratios tend to require large numbers, and are frequently represented as a fraction. More modern laws of chemistry define the relationship between energy and its transformations. Scientific law The laws of science, also called scientific laws or scientific principles, are statements that describe or predict a range of natural phenomena. Each scientific law is a statement based on repeated experimental observations that describes some aspect of the Universe. The term "law" has diverse usage in many cases (approximate, accurate, broad, or narrow theories) across all fields of natural science (physics,