Statement-I : There are two spherical nodes in 3s-orbital.
Because
Statement-II : There is no angular node in 3s-orbital.

Options

A. Statement-I is true, Statement-II is true , Statement-II is correct explanation for Statement-I.
B. Statement-I is true, Statement-II is true , Statement-II is NOT a correct explanation for statement-I
C. Statement-I is true, Statement-II is false
D. Statement-I is false, Statement-II is true

Answer

To analyze the statements provided in the question, we will break down the concepts of spherical nodes and angular nodes in atomic orbitals, specifically focusing on the 3s orbital.

### Step-by-Step Solution:

1. **Understanding the Quantum Numbers:**
- The principal quantum number (n) indicates the energy level of the electron in an atom. For the 3s orbital, n = 3.
- The azimuthal quantum number (l) defines the shape of the orbital. For s orbitals, l = 0.

2. **Formula for Spherical Nodes:**
- The number of spherical nodes in an orbital can be calculated using the formula:
\[ \text{Number of spherical nodes} = n - l - 1 \]
- For the 3s orbital:
- n = 3
- l = 0
- Substituting these values into the formula:
\[ \text{Number of spherical nodes} = 3 - 0 - 1 = 2 \]

3. **Conclusion about Spherical Nodes:**
- Therefore, there are indeed 2 spherical nodes in the 3s orbital, which confirms Statement-I.

4. **Understanding Angular Nodes:**
- Angular nodes are determined by the azimuthal quantum number (l). The number of angular nodes is equal to l.
- For the 3s orbital, since l = 0, the number of angular nodes is:
\[ \text{Number of angular nodes} = l = 0 \]
- This means that there are no angular nodes in the 3s orbital, confirming Statement-II.

5. **Evaluating the Relationship Between Statements:**
- Statement-I claims that there are two spherical nodes in the 3s orbital.
- Statement-II states that there is no angular node in the 3s orbital.
- While both statements are true, Statement-II does not provide a valid explanation for Statement-I. The presence of spherical nodes does not depend on the absence of angular nodes.

### Final Conclusion:
- Statement-I is true: There are two spherical nodes in the 3s orbital.
- Statement-II is true: There is no angular node in the 3s orbital.
- However, Statement-II does not explain Statement-I correctly.

Thus, the correct answer is that both statements are true, but Statement-II is not the correct explanation for Statement-I.