The Balmer series refers to the set of spectral lines in the visible region of the electromagnetic spectrum that are emitted by hydrogen atoms. These lines are produced when an electron in a hydrogen atom transitions from a higher energy level to the second energy level (n = 2).

Here is a detailed explanation of why the Balmer series falls in the visible region:

1. Energy levels in the hydrogen atom:
- The energy levels in a hydrogen atom are quantized, meaning that only certain discrete energy values are allowed.
- The lowest energy level is called the ground state, denoted by n = 1. Electrons in this state have the least amount of energy.
- Higher energy levels are represented by larger values of n. For example, the first excited state is n = 2, the second excited state is n = 3, and so on.

2. Transitions and emission of light:
- When an electron in a hydrogen atom transitions from a higher energy level to a lower energy level, it emits energy in the form of light.
- The energy of the emitted light corresponds to the energy difference between the initial and final energy levels of the electron.
- The wavelength of the emitted light can be determined using the formula:
λ = R(1/n₁² - 1/n₂²), where R is the Rydberg constant, n₁ is the initial energy level, and n₂ is the final energy level.

3. The Balmer series:
- The Balmer series corresponds to transitions where the electron starts in a higher energy level (n > 2) and ends in the second energy level (n = 2).
- The wavelengths of the spectral lines in the Balmer series can be calculated using the Balmer formula:
λ = 364.56 nm * (1/2² - 1/n²), where n is an integer ≥ 3.
- The resulting wavelengths fall in the visible region of the electromagnetic spectrum, ranging from approximately 400 nm (violet) to 700 nm (red).

In conclusion, the Balmer series of transitions in the spectrum of a hydrogen atom falls in the visible region because the emitted wavelengths correspond to light that can be detected by the human eye.

Balmer series of hydrogen spectrum falls under visible region...