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Assertion:The atomic size generally incr...

Assertion:The atomic size generally increases across a period and decreases down the group.
Reason:Atomic size depends upon valence shell electronic configuration.

A

a. Both Assertion and Reason are true and Reason is the correct explanation of Assertion.

B

b. Both Assertion and Reason are true and Reason is not the correct explanation of Assertion.

C

c. Assertion is true but Reason is false.

D

d.Both Assertion and Reason are false.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the assertion-reason question, we will analyze both the assertion and the reason step by step. ### Step 1: Understand the Assertion The assertion states: "The atomic size generally increases across a period and decreases down the group." - **Analysis**: This statement is incorrect. In reality, atomic size decreases as you move across a period (from left to right) due to the increasing nuclear charge which pulls the electrons closer to the nucleus. Conversely, atomic size increases as you move down a group because additional electron shells are added, which increases the distance between the nucleus and the outermost electrons. ### Step 2: Understand the Reason The reason states: "Atomic size depends upon valence shell electronic configuration." - **Analysis**: This statement is also misleading. While the valence shell electronic configuration does play a role in determining atomic size, the primary factor affecting atomic size is the effective nuclear charge. As the number of protons in the nucleus increases (along with the number of electrons), the effective nuclear charge increases, leading to a decrease in atomic size across a period. Therefore, this reason does not accurately explain the assertion. ### Step 3: Conclusion - Both the assertion and the reason are incorrect. The assertion incorrectly describes the trend of atomic size, and the reason does not accurately reflect the factors that influence atomic size. ### Final Answer Both assertion and reason are false.
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