Question

The third law of thermodynamics relates to

1. The entropy of a perfect crystal at absolute zero temperature.
2. The relation between work and heat.
3. Evolution of entropy of a system with time.
4. Conservation of mass.
Choose the correct answer from the options given below:

• (A) only.
• (B) only.
• (C) only.
• (D) only.

Hint:

The third law of thermodynamics states that at absolute zero, the entropy of a perfect crystal is zero.

Answer 1

The Correct Option is A

Step 1: Understand the third law of thermodynamics. The third law of thermodynamics states that the entropy of a perfect crystal at absolute zero temperature (0 K) is exactly zero. This is because, at 0 K, the system is in its ground state, and no randomness or disorder exists.
Step 2: Explanation of other options.
- (B): This refers to the first and second laws of thermodynamics.
- (C): Entropy evolution with time is a broader concept covered by the second law of thermodynamics.
- (D): Conservation of mass is described by the law of conservation of mass, not the third law of thermodynamics.
Step 3: Conclusion.
Thus, the third law of thermodynamics specifically deals with the entropy of a perfect crystal at absolute zero.
Final Answer: \[ \boxed{\text{(A) only}} \]