Different forms of energy are interconvertible. Energy can be converted from one form to another, but in the processes the total amount of energy must be conserved. Thus, for example, from the height and weight of the brick in the first sketch, we can predict exactly how much heat will be released when it hits the floor in the second sketch, note that the large amount of chemical bond energy released when water is formed is initially converted to very rapid thermal motions in the two new water molecules; however, collisions with other molecules almost instantaneously spread this kinetic energy evenly throughout the surroundings (heat transfer), making the new molecules indistinguishable from all the rest. Cells can convert chemical bond energy into kinetic energy to drive, for example, molecular motors, although without the intermediate conversions to electrical energy that an appliance such as a fan requires. They also harvest light energy to form chemical bonds.  Fair Use and Copyright info