Question

1. explain explain why this statement is false. \because there is no change in composition during a physical change, the appearance of the substance will not change.\

Explanation:

A physical change involves a change in the physical properties of a substance (like state, shape, size) without altering its chemical composition. For example, melting ice (solid to liquid water) or breaking a glass. In melting ice, the composition (H₂O) remains the same, but the appearance changes from a solid, crystalline structure to a liquid. Another example is dissolving sugar in water: the sugar's composition (C₁₂H₂₂O₁₁) doesn't change, but the appearance changes from solid crystals to a homogeneous solution. So, physical changes can alter appearance even with no compositional change.

Answer:

The statement is false because physical changes (no compositional change) can still alter a substance’s appearance. Physical changes affect physical properties (state, shape, size, etc.). For example, melting ice (solid → liquid, same \( \ce{H_2O} \) composition) or dissolving sugar (solid crystals → homogeneous solution, same sugar composition) change appearance despite no compositional change.