(A) : The radial probability distribution curves of `1s, 2p, 3d` orbitals are identical in shape
(R) : The number of nodal planes present in these orbitals is different

Options

A. Both (A) and R are true and R is the correct explanation of A.
B. Both (A) and R are true and R is not the correct explanation of A.
C. A is true R is false
D. A is false R is true

Answer

To solve the question, we need to analyze the assertion (A) and the reason (R) provided.

### Step 1: Understand the Assertion (A)
The assertion states that "The radial probability distribution curves of `1s, 2p, 3d` orbitals are identical in shape."

- **Radial Probability Distribution**: This refers to the probability of finding an electron at a certain distance from the nucleus, considering all angles. The shape of these curves can be similar in terms of the general appearance, but they differ in terms of the number of peaks and their distribution.

### Step 2: Understand the Reason (R)
The reason states that "The number of nodal planes present in these orbitals is different."

- **Nodal Planes**: These are regions where the probability of finding an electron is zero. The number of nodal planes is determined by the azimuthal quantum number (l). For the orbitals in question:
- `1s` (l = 0): 0 nodal planes
- `2p` (l = 1): 1 nodal plane
- `3d` (l = 2): 2 nodal planes

### Step 3: Analyze the Truth of A and R
- **Is A True?**: The assertion is partially true. While the radial probability distribution curves may appear similar, they are not identical in shape due to differences in the number of peaks and nodal planes.
- **Is R True?**: The reason is true; the number of nodal planes is indeed different for `1s`, `2p`, and `3d` orbitals.

### Step 4: Conclusion
Both A and R are true, but R does not correctly explain A. Therefore, the correct answer is:
- **Both A and R are true, but R is not the correct explanation of A.**

### Final Answer:
Both A and R are true, but R is not the correct explanation of A.

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