A change from one state (solid or liquid or gas) to another without a change in chemical composition is called what?

A change from one state (solid or liquid or gas) to another without a change in chemical composition is called what?

• A. Phase change
• B. Freezing
• C. Melting point
• D. Boiling point

Answer: (A)

Phase change is the term for a change from one state of matter to another without changing the chemical composition. This happens when energy is added or removed, allowing particles to rearrange into a different arrangement while keeping the same molecules. Examples include solid to liquid (melting), liquid to solid (freezing), liquid to gas (vaporization), gas to liquid (condensation), solid to gas (sublimation), and gas to solid (deposition). The melting point and boiling point are the temperatures where specific phase changes occur, not the process as a whole. Freezing is one particular phase change, while melting point and boiling point describe when those changes happen.

Phase change is the term for a change from one state of matter to another without changing the chemical composition. This happens when energy is added or removed, allowing particles to rearrange into a different arrangement while keeping the same molecules. Examples include solid to liquid (melting), liquid to solid (freezing), liquid to gas (vaporization), gas to liquid (condensation), solid to gas (sublimation), and gas to solid (deposition). The melting point and boiling point are the temperatures where specific phase changes occur, not the process as a whole. Freezing is one particular phase change, while melting point and boiling point describe when those changes happen.