Which one of the following orbitals is spherical in shape ?

Options

A. (a) 4s
B. (b) 3p
C. (c) 3d
D. (d) 4f

Answer

To determine which orbital is spherical in shape, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Types of Orbitals**:
- The main types of orbitals are s, p, d, and f orbitals. Each has a distinct shape.

2. **Understand the Shape of s Orbitals**:
- The s orbital is known for its spherical shape. It is symmetrical in all directions around the nucleus.

3. **Understand the Shape of p Orbitals**:
- The p orbitals have a dumbbell shape. They are elongated and have two lobes on either side of the nucleus.

4. **Understand the Shape of d Orbitals**:
- The d orbitals have a double dumbbell shape. They are more complex and can have different orientations in space.

5. **Understand the Shape of f Orbitals**:
- The f orbitals are even more complex than d orbitals and do not have a simple geometric shape.

6. **Conclusion**:
- Since the question asks for the orbital that is spherical in shape, we conclude that the s orbital is the only one that fits this description. Therefore, if the options include an s orbital (like 4s), that would be the correct answer.

### Final Answer:
The orbital that is spherical in shape is the **s orbital** (e.g., 4s).

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