Question

Assertion: Naphthalene balls become smaller gradually
Reason: Naphthalene balls go under sublimation; hence it changes into vapor without changing into liquid
A.Both Assertion and Reason are correct and Reason is the correct explanation of Assertion
B.Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion
C.Assertion is correct but Reason is incorrect
D.Both Assertion and Reason are incorrect

Answer 1

Hint: Sublimation is the transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase. Naphthalene is the solid that can be sublimed under the standard atmospheric temperature with the sublimation point at around $80^\circ C$ or $176^\circ F$ .

Complete Step by Step Solution:
Naphthalene is the aromatic compound. It is the aromatic hydrocarbon which is found in the crude oil or coal tar. It can be used for the production of plastics, resins, fuels and dyes.
In the question, naphthalene balls undergo the sublimation. So, the sublimation is the transition of the substance from the solid state to the gaseous state without passing from the liquid phase.
The naphthalene balls are kept with clothes or some other documents to protect them from the insects as the naphthalene balls undergo the process of sublimation it changes into vapor without changing into liquid phase and the vapor of naphthalene balls defends the materials from getting destroyed.
The sublimation of naphthalene balls makes them very small and after sometimes they disappear from the environment as they go away in the form of vapour due to sublimation.
Hence, both assertion and reason are correct and reason is the correct explanation of the assertion.

Hence, the correct answer is option A.

Note: As the naphthalene balls do not leave any solid during the process of sublimation their size gradually decreases and they disappear.