To determine which statement is correct regarding nodes in atomic orbitals, we can analyze the definitions and formulas related to nodes, radial nodes, and angular nodes.
### Step-by-Step Solution:
1. **Understanding Nodes**:
- A node is a region in an atomic orbital where the probability of finding an electron is zero. There are two types of nodes: radial nodes and angular nodes.
2. **Types of Nodes**:
- **Radial Nodes**: These are spherical in nature. The number of radial nodes can be calculated using the formula:
\[
\text{Radial Nodes} = n - l - 1
\]
where \( n \) is the principal quantum number and \( l \) is the azimuthal quantum number.
- **Angular Nodes**: These are planar nodes. The number of angular nodes is given by:
\[
\text{Angular Nodes} = l
\]
3. **Total Number of Nodes**:
- The total number of nodes in an orbital is given by:
\[
\text{Total Nodes} = n - 1
\]
4. **Evaluating the Statements**:
- **Statement A**: "The number of angular nodes is \( n - l - 1 \)" - This is incorrect because the number of angular nodes is simply \( l \).
- **Statement B**: "The number of radial nodes is \( l \)" - This is also incorrect because the number of radial nodes is \( n - l - 1 \).
- **Statement C**: "The total number of nodes is \( n - 1 \)" - This is correct.
- **Statement D**: (not provided, but assuming it is incorrect based on the context).
5. **Conclusion**:
- The correct statement is **Statement C**: "The total number of nodes is \( n - 1 \)".
### Final Answer:
The correct statement is: **The total number of nodes is \( n - 1 \)**.
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