Consider the following statements regarding matter: 1. Elements cannot be broken down into simpler substances. 2. A compound has a variable composition and can be broken down into elements. 3. Dissolution of sulphur in carbon disulphide is an example of a homogeneous mixture. Which of the statements given above is/are not correct?

Statement 1 is correct: by definition, elements are pure substances that cannot be broken down into simpler substances by chemical means. Statement 2 is incorrect: a compound has a fixed and definite composition (law of definite proportions), not a variable one, although it can indeed be broken down into elements. Statement 3 is correct: sulphur dissolves in carbon disulphide to form a clear, uniform solution, which is a homogeneous mixture. Therefore, only statement 2 is not correct.