This section contains Assertion and Reason type question each question has 4 choices (1)(2)(3)(4) out of which only one is correct
Assertion(A):`NH_3` molecules is `AB_3 `type
Reason(R):The geometry of `NH_3` molecules is pyramidal

Options

A. Both Assertion and Reason are correct and Reason is the correct explanation of the 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

To solve the assertion and reason question regarding the ammonia molecule (NH₃), we will analyze both the assertion and the reason step by step.

### Step 1: Understand the Assertion
- **Assertion (A)**: "NH₃ molecules is AB₃ type."
- The AB₃ type refers to a molecule where one central atom (A) is bonded to three other atoms (B). In the case of NH₃, nitrogen (N) is the central atom and it is bonded to three hydrogen (H) atoms. Therefore, the assertion is correct.

### Step 2: Understand the Reason
- **Reason (R)**: "The geometry of NH₃ molecules is pyramidal."
- The geometry of NH₃ is indeed trigonal pyramidal due to the presence of a lone pair of electrons on the nitrogen atom. This lone pair repels the bonding pairs, resulting in a pyramidal shape. Thus, the reason is also correct.

### Step 3: Analyze the Relationship Between Assertion and Reason
- While both the assertion and reason are correct, we need to determine if the reason correctly explains the assertion.
- The assertion states that NH₃ is AB₃ type, which is correct. However, the reason states that the geometry is pyramidal, which is true but does not directly explain why NH₃ is classified as AB₃ type. The classification as AB₃ is based on the number of bonding pairs, while the geometry is a result of both bonding pairs and lone pairs.

### Conclusion
- Both the assertion and reason are correct, but the reason does not adequately explain the assertion. Therefore, the correct choice is:
- **Option 2**: Both A and R are correct, but R is not the correct explanation of A.