Abstract
The law of conservation of energy states that the total amount of energy in an isolated system remains constant. A consequence of this law is that energy cannot be created nor destroyed. Changes in energy in systems can only be accomplished by adding or subtracting energy from them, as energy is a quantity which is conserved. Energy in a system may be transformed so that it resides in a different state. Energy in many states may be used to do many varieties of physical work. Energy may be used in natural processes or machines, or else to provide some service to society, such as heat, light, or motion. Energy may be transformed so that it may be used by other natural processes or machines, or else to provide some service to society. For example, an internal combustion engine converts the potential chemical energy in gasoline and oxygen into the propulsive energy that moves a vehicle. A solar cell converts solar radiation into electrical energy that can then be used to light a bulb or power a computer. All biomass is produced by green plants converting sunlight into plant material through photosynthesis. Photosynthesis is a carbon fixation reaction by reduction of carbon dioxide. The fixation or reduction of carbon dioxide is a light-independent process.