Question 12

A student walks to school and notices frost on the grass; when they walk home, the grass is dry.

This scenario illustrates sublimation, where frost (solid water) transitions directly into vapor without becoming liquid water, resulting in the grass being dry upon the student's return.

A) A student walks to school and notices frost on the grass; when they walk home, the grass is dry

This option correctly exemplifies sublimation, as it describes frost disappearing directly into vapor as the temperature rises, demonstrating the phase change from solid to gas without passing through the liquid state.

B) A bus driver observed dew on the windshield in the morning it dried after driving

This option describes the evaporation of liquid water (dew) from the windshield as the bus heats up, which is a phase change from liquid to gas, not sublimation.

C) A parent sees snow on the steps when arising, but a puddle of water when exiting the house

This scenario involves snow (solid) melting into water (liquid), which is a process of melting rather than sublimation, as it involves a transition from solid to liquid before becoming vapor.

D) None of the above

This option is incorrect because option A provides a clear example of sublimation. Therefore, stating that none of the options exemplify sublimation is inaccurate.

Conclusion

Option A is definitively correct as it accurately depicts the process of sublimation, where frost transitions directly into vapor. All other options either describe different processes or do not provide an example of sublimation, highlighting the importance of understanding phase changes in substances.