The orbital angular momentum of electron in 4s orbital of H atom is ……….

Explanation

To find the orbital angular momentum of an electron in the 4s orbital of a hydrogen atom, we can follow these steps:

### Step 1: Understand the Quantum Numbers
The first step is to identify the quantum number associated with the 4s orbital. The principal quantum number (n) for the 4s orbital is 4. The azimuthal quantum number (l) for an s orbital is always 0.

### Step 2: Use the Formula for Orbital Angular Momentum
The formula for the orbital angular momentum (L) of an electron is given by:
\[ L = \sqrt{l(l + 1)} \cdot \frac{h}{2\pi} \]
where:
- \( l \) is the azimuthal quantum number,
- \( h \) is Planck's constant.

### Step 3: Substitute the Values
Since we have identified that for the 4s orbital, \( l = 0 \):
\[ L = \sqrt{0(0 + 1)} \cdot \frac{h}{2\pi} \]
\[ L = \sqrt{0} \cdot \frac{h}{2\pi} \]

### Step 4: Calculate the Orbital Angular Momentum
Since the square root of 0 is 0:
\[ L = 0 \cdot \frac{h}{2\pi} = 0 \]

### Conclusion
The orbital angular momentum of the electron in the 4s orbital of the hydrogen atom is **0**.

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