Balmer Series

Definition

The Balmer series is a series of spectral lines in the visible and ultraviolet regions of the electromagnetic spectrum that are emitted by hydrogen atoms when electrons transition from higher energy levels to the second energy level. This series of spectral lines is named after the Swiss mathematician and physicist Johann Balmer, who discovered the mathematical formula that describes the wavelengths of these lines.

5 Must Know Facts For Your Next Test

1. The Balmer series includes four visible spectral lines with wavelengths of 656.3 nm (red), 486.1 nm (blue-green), 434.0 nm (blue), and 410.2 nm (violet).
2. The Balmer series is produced when electrons in a hydrogen atom transition from higher energy levels (n ≥ 3) to the second energy level (n = 2).
3. The wavelengths of the Balmer series lines can be calculated using the Balmer formula: $\lambda = \frac{364.56}{n^2 - 2^2}$ nm, where $n$ is the energy level to which the electron transitions.
4. The Balmer series is important in the study of stellar spectra, as it is commonly observed in the spectra of stars and can be used to determine the presence and properties of hydrogen in the stellar atmosphere.
5. The Balmer series is also observed in the spectra of other hydrogen-containing gases, such as those found in nebulae and the solar atmosphere.

Review Questions

• Explain how the Balmer series is related to the formation of spectral lines in astronomy.
  • The Balmer series is a key component of the atomic emission spectrum of hydrogen, which is the simplest and most abundant element in the universe. When the electrons in hydrogen atoms transition from higher energy levels to the second energy level, they emit photons with specific wavelengths that correspond to the Balmer series. These discrete spectral lines can be observed in the spectra of stars, nebulae, and other astronomical objects containing hydrogen, allowing astronomers to study the properties and composition of these objects.
• Describe how the Doppler effect can be used in conjunction with the Balmer series to study the motion of interstellar gas.
  • The Balmer series lines in the spectra of interstellar gas can be used in combination with the Doppler effect to measure the motion of that gas. As the interstellar gas moves relative to the observer, the wavelengths of the Balmer series lines will be shifted due to the Doppler effect. By analyzing the magnitude and direction of this shift, astronomers can determine the velocity and direction of the gas, providing valuable information about the dynamics and structure of the interstellar medium.
• Explain the significance of the Balmer series in the context of the formation of spectral lines and how it relates to our understanding of the hydrogen atom and its energy levels.
  • The Balmer series is a fundamental aspect of the formation of spectral lines, as it demonstrates the discrete energy levels of the hydrogen atom and the transitions between those levels. The Balmer formula, which describes the wavelengths of the Balmer series lines, is a direct consequence of the quantum mechanical model of the hydrogen atom, where electrons can only occupy specific, quantized energy levels. The observation and analysis of the Balmer series has been instrumental in developing our understanding of atomic structure and the behavior of electrons within atoms, which is a cornerstone of modern physics and chemistry.

Related terms

Atomic Emission Spectrum: The set of discrete wavelengths of light emitted by an atom when its electrons transition between energy levels.

Hydrogen Atom: The simplest atom, consisting of a single proton in the nucleus and a single electron orbiting the nucleus.

Energy Levels: The discrete energy states that an electron can occupy within an atom, determined by the quantum mechanical properties of the atom.