Which term describes a process in which no new substances are formed and the identity of the matter does not change?

• A. Chemical change
• B. Nuclear change
• C. Phase change
• D. Physical change

Answer: (D)

The main idea is recognizing when a change does not alter what the substance actually is. In a physical change, the material stays the same substance—its chemical formula doesn’t change and no new substance forms. You might change its shape, size, or state (solid, liquid, gas), but it remains the same matter. For example, ice melting or water boiling are physical changes because you still have H2O at a different temperature or phase, not something new. Dissolving sugar, crushing a stone, or tearing paper are other examples where the identity remains, even though appearances differ. Phase changes are part of this category, since the state changes but the chemical identity doesn’t. Since no new substances are produced and the substance’s identity stays the same, this is best described as a physical change.