Question

during which changes of state does the motion of the atoms decrease?
○ melting and deposition
○ freezing and condensation
○ condensation and evaporation
○ vaporization and sublimation

Explanation:

To determine when atom motion decreases, we analyze state changes:

• Freezing: Liquid to solid (atoms slow, less motion).
• Condensation: Gas to liquid (atoms slow, less motion).
• Other options (e.g., melting, evaporation, vaporization, sublimation) involve increasing atom motion (energy absorption, phase changes to more energetic states). Deposition (gas to solid) also slows atoms, but "melting and deposition" is incorrect (melting increases motion). "Condensation and evaporation" is wrong (evaporation increases). "Vaporization and sublimation" are energy - absorbing, increasing motion. Thus, freezing and condensation are correct.

Answer:

B. freezing and condensation