The electron in hydrogen atom is initially in the third excited state. What is the maximum number of spectral lines which can be emitted, when it finally moves to the ground state?

Explanation

To find the maximum number of spectral lines emitted when an electron in a hydrogen atom transitions from the third excited state to the ground state, we can follow these steps:

### Step 1: Identify the initial state
The electron is in the third excited state. In terms of quantum numbers, the ground state corresponds to n=1, the first excited state corresponds to n=2, the second excited state corresponds to n=3, and the third excited state corresponds to n=4. Therefore, the electron starts at n=4.

### Step 2: Determine the final state
The final state is the ground state, which corresponds to n=1.

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