Ohio Assessment for Educators (OAE) Integrated Science (024) Practice Exam

Which law explains that when energy changes from one form to another, some is degraded into lower quality energy?

1. First Law of Thermodynamics

2. Second Law of Thermodynamics

3. Third Law of Thermodynamics

4. Law of Conservation of Energy

The correct answer is: Second Law of Thermodynamics

The Second Law of Thermodynamics is the principle that addresses the degradation of energy when it is transformed from one form to another. This law states that in any energy transfer or transformation, the total entropy of a closed system will tend to increase over time, indicating that energy becomes less usable as it is converted. This explains why some of the energy is degraded into lower quality energy, often in the form of heat, which is less useful for doing work. The notion of entropy is central to this law—it represents the degree of disorder or randomness in a system, which tends to increase, leading to energy dispersal and loss of energy quality. Therefore, when energy conversions occur, like turning chemical energy in fossil fuels into kinetic energy in movement, some of that energy is converted to heat and thus lost to the system's useful work. The other laws mentioned focus on different aspects of energy and thermodynamics. The First Law of Thermodynamics pertains to the conservation of energy, asserting that energy cannot be created or destroyed, only transformed. The Third Law addresses the behavior of systems as they approach absolute zero temperature. Lastly, the Law of Conservation of Energy, while closely related to the First Law, emphasizes that energy remains constant in isolation but does not discuss the quality of