Which term describes the phase change process from one state to another without chemical change?

Which term describes the phase change process from one state to another without chemical change?

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

Answer: (A)

The main idea being tested is that some changes move a substance between solid, liquid, and gas without changing its chemical identity. This broader category is called a phase change. In a phase change, energy is absorbed or released to overcome or strengthen intermolecular forces, but the molecules aren’t transformed into new substances. Freezing is one example of a phase change, from liquid to solid, while melting point and boiling point describe the specific temperatures at which solids become liquids and liquids become gases, respectively. Since the question asks for the general process, the umbrella term phase change best fits.

The main idea being tested is that some changes move a substance between solid, liquid, and gas without changing its chemical identity. This broader category is called a phase change. In a phase change, energy is absorbed or released to overcome or strengthen intermolecular forces, but the molecules aren’t transformed into new substances. Freezing is one example of a phase change, from liquid to solid, while melting point and boiling point describe the specific temperatures at which solids become liquids and liquids become gases, respectively. Since the question asks for the general process, the umbrella term phase change best fits.