Atomic Spectral Series: Basics

Atomic spectral series are fundamental concepts in understanding atomic structure and spectroscopy. They represent groups of spectral lines corresponding to electron transitions between specific energy levels in an atom. Each series is defined by the principal quantum number of the electron's final energy state ($n_f$) after it emits a photon.

The key spectral series mentioned are:

• Lyman Series: Defined by electron transitions that end in the ground state, where $n_f = 1$.
• Balmer Series: Defined by electron transitions that end in the first excited state, where $n_f = 2$.
• Paschen Series: Defined by electron transitions that end in the second excited state, where $n_f = 3$.
• Pfund Series: Defined by electron transitions that end in the fourth excited state, where $n_f = 5$.

The energy of the emitted photon is directly related to the energy difference between the electron's initial and final states. Larger energy differences result in higher energy photons (shorter wavelengths), while smaller energy differences result in lower energy photons (longer wavelengths).

Electromagnetic Spectrum Ranges Defined

The electromagnetic spectrum organizes different types of radiation based on their energy, frequency, and wavelength. The ranges pertinent to this question are:

• Microwave Range: Characterized by very low energy and long wavelengths.
• Ultraviolet Range: Possesses higher energy and shorter wavelengths than visible light.
• Visible Range: The specific portion of the electromagnetic spectrum detectable by the human eye.
• Infrared Range: Has lower energy and longer wavelengths compared to visible light.

Spectral Series to Energy Range Matching

This question requires matching each spectral series listed in LIST-I with its corresponding region in the electromagnetic spectrum from LIST-II. The matching depends on the energy of the photons emitted during the electron transitions defining each series.

Based on the provided correct answer, the pairings are established as follows:

Detailed Match Analysis (Based on Provided Answer)

Let's analyze each pairing presented in the correct answer:

• A. Lyman Series - Microwave Range: This pairing associates the Lyman series (transitions to $n_f = 1$) with the Microwave range.
• B. Balmer Series - Ultraviolet Range: The Balmer series (transitions to $n_f = 2$) is matched with the Ultraviolet range.
• C. Paschen Series - Infrared Range: This match connects the Paschen series (transitions to $n_f = 3$) with the Infrared range. This alignment corresponds to transitions involving lower energy differences emitting lower energy photons.
• D. Pfund Series - Visible Range: The Pfund series (transitions to $n_f = 5$) is paired with the Visible range.

Identifying the Correct Option

We must identify the option that correctly lists the pairings A-I, B-II, C-IV, and D-III.

Let's review the given options:

• Option 1: A-I, B-II, C-III, D - IV
• Option 2: A-II, B-III, C-I, D - IV
• Option 3: A-I, B-II, C - IV, D - III
• Option 4: A-II, B-III, C-IV, D-I

Comparing the required pairings (A-I, B-II, C-IV, D-III) with the options, we find that Option 3 precisely matches these pairings.