The orbital without nodal plane is

Options

A. 1s
B. 2p
C. 3d
D. 3p

Answer

To determine which orbital has no nodal planes, we need to understand the concept of nodal planes in atomic orbitals.

### Step-by-Step Solution:

1. **Understanding Nodal Planes:**
- Nodal planes are regions in an orbital where the probability of finding an electron is zero. This means that if you were to slice through the orbital at that plane, there would be no electrons present.

2. **Analyzing the Given Orbitals:**
- **1s Orbital:**
- The 1s orbital has a spherical shape. Since it is spherical, the probability of finding an electron is non-zero everywhere around the nucleus. Therefore, the 1s orbital has **zero nodal planes**.
- **2p Orbital:**
- The 2p orbital has a dumbbell shape. There is a nodal plane that passes through the nucleus, which means the probability of finding an electron is zero at that plane. Thus, the 2p orbital has **one nodal plane**.
- **3d Orbital:**
- The 3d orbital has a more complex shape, often described as a double dumbbell. There are multiple nodal planes in the 3d orbital, typically **two nodal planes**.
- **3p Orbital:**
- Similar to the 2p orbital, the 3p orbital also has a dumbbell shape and contains **one nodal plane**.

3. **Conclusion:**
- Among the options provided:
- 1s has zero nodal planes (correct answer).
- 2p has one nodal plane (incorrect).
- 3d has two nodal planes (incorrect).
- 3p has one nodal plane (incorrect).
- Therefore, the correct answer is **1s orbital**.

### Final Answer:
The orbital without nodal plane is **1s**.