Which of the following statement regarding spectral series is/are correct ?

Options

A. The lines in the Balmer series correspond to the electronic transition from the energy levels higher than n = 1 energy level
B. Paschen series appear in the infrared region
C. The line of Lyman series appear in the visible region
D. Transition from higher energy levels to 5th energy level produces Pfund series which falls in the infrared region

Answer

To determine which statements regarding spectral series are correct, we will analyze each option step by step.

### Step 1: Analyze the first option
**Statement:** The lines in the Balmer series correspond to the electronic transition from the energy level higher than n = 1.

**Analysis:**
- The Balmer series involves transitions where electrons fall to the n = 2 energy level (n1 = 2).
- The transitions can occur from n = 3, 4, 5, etc. (n2 = 3, 4, 5, ...).
- Therefore, the statement is incorrect because the transitions start from n = 3, which is higher than n = 2, not n = 1.

**Conclusion:** The first option is **incorrect**.

### Step 2: Analyze the second option
**Statement:** Paschen series appears in the infrared region.

**Analysis:**
- The Paschen series involves transitions where electrons fall to the n = 3 energy level (n1 = 3).
- The transitions can occur from n = 4, 5, 6, etc. (n2 = 4, 5, 6, ...).
- The Paschen series is indeed located in the infrared region.

**Conclusion:** The second option is **correct**.

### Step 3: Analyze the third option
**Statement:** The lines of Lyman series appear in the visible region.

**Analysis:**
- The Lyman series involves transitions where electrons fall to the n = 1 energy level (n1 = 1).
- The transitions can occur from n = 2, 3, 4, etc. (n2 = 2, 3, 4, ...).
- The Lyman series is located in the ultraviolet region, not the visible region.

**Conclusion:** The third option is **incorrect**.

### Step 4: Analyze the fourth option
**Statement:** Transition from the high energy level to the fifth energy level produces the Pfund series, which falls in the infrared region.

**Analysis:**
- The Pfund series involves transitions where electrons fall to the n = 5 energy level (n1 = 5).
- The transitions can occur from n = 6, 7, 8, etc. (n2 = 6, 7, 8, ...).
- The Pfund series is indeed located in the infrared region.

**Conclusion:** The fourth option is **correct**.

### Final Conclusion
- The correct statements regarding spectral series are:
- Option 2: Paschen series appears in the infrared region (Correct).
- Option 4: Transition from high energy level to the fifth energy level produces the Pfund series, which falls in the infrared region (Correct).

### Summary of Correct Options
- **Correct Options:** 2 and 4
- **Incorrect Options:** 1 and 3

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