What does the first law of thermodynamics imply about energy transformations?

• A. Energy can only be created
• B. Energy can be neither created nor destroyed
• C. Energy is always lost in transformations
• D. Energy can only be destroyed

Answer: (B)

The first law of thermodynamics, also known as the law of energy conservation, states that the total energy of an isolated system remains constant; it can neither be created nor destroyed but can only be transformed from one form to another. This principle highlights the idea that all energy transfers or transformations—such as converting chemical energy in food to kinetic energy in movement—maintain a balance. For example, when a car burns gasoline, the chemical energy stored in the fuel is converted into kinetic energy for motion, while producing heat as a byproduct.

This understanding also underscores why the other choices do not align with the law: energy cannot be created from nothing, nor can it simply be lost without a trace; it transmutes into different forms. Therefore, the assertion that energy can be neither created nor destroyed captures the essence of the first law and clarifies the framework within which we understand energy conservation in physical processes.