Second Law of Thermodynamics Explained
The second law of thermodynamics fundamentally deals with the directionality of natural processes and the concept of entropy.
Let's analyze the options:
- Option 1 and Option 2 describe the First Law of Thermodynamics, which states that energy is conserved and cannot be created or destroyed.
- Option 3 describes the Third Law of Thermodynamics, which relates entropy to absolute zero temperature.
- Option 4 states: "When an isolated system undergoes a spontaneous change, the entropy of the universe increases." This statement accurately captures a core principle of the Second Law of Thermodynamics. Spontaneous processes naturally proceed in a direction that increases the total entropy of the universe (system + surroundings). For an isolated system, the universe is just the system itself, hence its entropy increases.
Therefore, Option 4 is the best description.