Which of the following is NOT a correct statement of the first law of thermodynamics?

• A. The change in internal energy of a system equals the heat added to the system minus the work done by the system.
• B. Energy can be created or destroyed in an isolated system.
• C. The total energy of an isolated system remains constant.
• D. Energy can be transformed from one form to another, but cannot be created or destroyed.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the first law of thermodynamics, which states that energy cannot be created or destroyed in an isolated system; it can only be transformed or transferred. This means the total energy of an isolated system remains constant.
2. Step 2: Recognize the mathematical expression of the first law: \(\Delta U = Q - W\), where \(\Delta U\) is the change in internal energy of the system, \(Q\) is the heat added to the system, and \(W\) is the work done by the system.
3. Step 3: Analyze each statement given in the problem to see if it aligns with the first law: the statement about the change in internal energy equaling heat added minus work done is correct and matches the formula.
4. Step 4: The statement that the total energy of an isolated system remains constant is also correct, as it reflects conservation of energy.
5. Step 5: The statement that energy can be transformed from one form to another but cannot be created or destroyed is a fundamental principle of the first law and is correct. Therefore, the incorrect statement is the one claiming that energy can be created or destroyed in an isolated system, which contradicts the first law.