The correct option is 1 only
Explanation
Matter is broadly classified into pure substances (elements and compounds) and mixtures. The distinction relies on the nature of the interaction between components, the uniformity of their distribution, and the methods required to separate them.
Statement-wise Analysis:
- Statement 1 is Correct: A homogeneous mixture is characterized by a uniform composition and properties throughout its entire mass. The components are mixed at the molecular level and are not distinguishable. Examples include air, alloys, and true solutions (like salt in water).
- Statement 2 is Incorrect: A compound is a pure substance formed by the chemical combination of elements. The constituents of a compound are held together by strong chemical bonds and can only be separated by chemical or electrochemical reactions. Physical methods (such as filtration, distillation, or magnetic separation) are effective only for separating mixtures, not compounds.
- Statement 3 is Incorrect: A mixture possesses a variable composition. The components can be combined in any ratio (e.g., sand and salt). In contrast, a compound always has a fixed composition by mass, governed by the Law of Definite Proportions.
Key Takeaway:
The fundamental difference between mixtures and compounds lies in their composition and separation: mixtures have variable composition and are separable by physical means, while compounds have fixed composition and require chemical means for separation.