Why is it possible to use physical properties to separate a mixture back into its original parts?

• A. Because the components of a mixture undergo chemical reactions that make them easier to separate.
• B. Because mixtures always consist of elements with identical physical properties.
• C. Because physical properties change when substances are mixed, making separation possible.
• D. Because the components of a mixture retain their individual physical properties, allowing separation by methods such as filtration or distillation.

Answer: (D)

Verified step by step guidance

1. Understand that a mixture is composed of two or more substances combined physically, not chemically, so each component retains its own physical properties.
2. Recognize that physical properties include characteristics like boiling point, melting point, solubility, density, and particle size, which differ among the components of a mixture.
3. Know that because these physical properties remain unchanged in a mixture, we can exploit differences in these properties to separate the components without altering their chemical identities.
4. Examples of separation techniques include filtration (based on particle size), distillation (based on boiling points), and chromatography (based on solubility and affinity), all relying on physical property differences.
5. Therefore, the key reason physical properties allow separation is that the components do not chemically react or change, so their distinct physical characteristics can be used to isolate them.