Question

Would a pure substance ever settle out and form two distinct layers? Explain your reasoning.

Options:
Option 1: Yes, because pure substances can separate based on their density.
Option 2: No, because pure substances always remain uniformly mixed.
Option 3: Yes, because pure substances can separate based on their temperature.
Option 4: No, because pure substances cannot undergo phase separation.

Answer 1

No, a pure substance would not form two distinct layers because its constant composition and properties ensure that it remains uniform throughout.

Step-by-step explanation:

A pure substance would not settle out and form two distinct layers because it is a form of matter that has a constant composition and properties. Pure substances are either elements or compounds, and they are uniform throughout in their chemical composition.

Phase changes, such as melting and boiling, occur at specific temperatures for pure substances, and this is a key characteristic that distinguishes them from mixtures. If a substance is pure, it will not separate into different phases under stable temperature and pressure conditions because it doesn't contain more than one component that could separate out. Therefore, the correct answer is 'No, because pure substances cannot undergo phase separation.'