Chemistry Regents Practice Test 2025 – The All-in-One Guide to Exam Success!

During sublimation, a solid changes directly into a gas without passing through the liquid state. This process involves the input of energy, which allows the molecules within the solid to overcome the forces that hold them in a fixed structure. Instead of transitioning into a liquid first, the molecules gain enough kinetic energy to escape directly into the vapor phase.

Common examples of sublimation include dry ice (solid carbon dioxide) transitioning into carbon dioxide gas and snow or ice sublimating in cold, dry air. Understanding this process is crucial as it illustrates the different phases of matter and how substances can shift between these phases under various conditions.

The other options describe different phase changes. When a liquid turns into a vapor, it is boiling or evaporating, not sublimating. The condensation of a gas into a solid is known as deposition. Finally, when a liquid freezes into a solid, it is undergoing solidification. Each of these processes reflects a distinct transformation of matter, highlighting the unique nature of sublimation as a solid-to-gas transition.