Let us pass electric current through the discharge tube. The gas emits blue light, because the atoms of hydrogen gas gain energy from the current and get excited. When the excited atoms return to the normal state, they emit energy, in the visible region, which appears blue. If this blue light is passed through a prism, the light breaks into 5 colours apearing as lines of four colours. This is known as the line emission spectrum of hydrogen. When the spectrum of investigated in infra red and ulltraviolet regions, more lines were found, which were given different names. Such as, Lyman, Balmer, Paschen, Brackett and Pfund series. the wavelengths of the lines followed the expression: v bar =v/c=rh/hc (1/ni^2-1/nf^2) An electron in a Hydrogen atom can be excited to many higher energy levels by absorption of radiation and thus, increasing the energy of electron. When the electron is present in the higher energy levels, to stabilize itself it jumps to lower energy levels and emits radiation. For example, if an electron is present in 5th energy level, it may jump back either directly, to lowest energy level, or it may undergo succesive downward displacement from 5th energy level to 4th energy level and so on. These downward displacements are associated with different amount of energies, and hence lead to emission of radiation of different wavelengths. Thus, giving rise to different lines in hydrogen spectrum.

Hydrogen Spectrum

The hydrogen spectrum refers to the emission spectrum of hydrogen gas when it is excited by a high-voltage electrical discharge. This phenomenon was first observed by the physicist Johann Balmer in 1885 and later explained by Niels Bohr in 1913 using his atomic model. The hydrogen spectrum is significant because it provides valuable insights into the energy levels of the hydrogen atom and the principles of quantum mechanics.

The Balmer Series

The Balmer series is a specific set of spectral lines within the hydrogen spectrum. These lines appear in the visible region of the electromagnetic spectrum and correspond to transitions between different energy levels in the hydrogen atom. The Balmer series is characterized by four distinct wavelengths, known as Balmer lines, which are given by the formula:

1/λ = R_H(1/2^2 - 1/n^2)

Where λ is the wavelength of the emitted light, R_H is the Rydberg constant, and n is an integer representing the energy level of the atom.

Transitions and Energy Levels

The hydrogen atom consists of a single proton in the nucleus and an electron orbiting around it. According to Bohr's model, the electron can only occupy certain discrete energy levels, and when it transitions between these levels, it emits or absorbs energy in the form of photons.

Lyman, Paschen, and Brackett Series

In addition to the Balmer series, there are other series of spectral lines within the hydrogen spectrum. These include the Lyman series, which corresponds to ultraviolet wavelengths, the Paschen series, which corresponds to infrared wavelengths, and the Brackett series, which also falls in the infrared region.

Applications of the Hydrogen Spectrum

The hydrogen spectrum has several applications in various fields of science and technology. It has been used to determine the composition and properties of distant stars and galaxies by analyzing their emission spectra. Additionally, the hydrogen spectrum plays a crucial role in atomic physics research, helping scientists understand the behavior of atoms and the principles of quantum mechanics.

In conclusion, the hydrogen spectrum is a fascinating phenomenon that provides valuable information about the energy levels and transitions in the hydrogen atom. By analyzing the spectrum, scientists can gain insights into the fundamental principles of atomic physics and quantum mechanics, as well as make important observations in astronomy and other scientific fields.