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💏intro to chemistry review

Stationary States

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Stationary states are specific energy levels within an atom where an electron can exist without radiating energy. These discrete energy levels are a fundamental concept in the Bohr model of the atom, which describes the behavior of electrons and their interactions with the nucleus.

5 Must Know Facts For Your Next Test

  1. Electrons in stationary states do not emit or absorb energy, as they are not changing energy levels.
  2. The Bohr model states that electrons can only exist in certain fixed, or stationary, energy levels within the atom.
  3. Transitions between stationary states involve the absorption or emission of a specific amount of energy, corresponding to the energy difference between the levels.
  4. The energy of a stationary state is determined by the principal quantum number, which is a positive integer that describes the shell or orbit of the electron.
  5. Stationary states are a crucial concept in understanding atomic structure and the behavior of electrons, as they form the foundation for the Bohr model and quantum mechanical descriptions of the atom.

Review Questions

  • Explain the significance of stationary states in the Bohr model of the atom.
    • In the Bohr model, electrons can only occupy specific, discrete energy levels within the atom, known as stationary states. These stationary states are crucial because they define the allowed energy levels for the electrons and govern the transitions between them. Electrons in stationary states do not emit or absorb energy, but when they transition between these states, they either release or absorb a specific amount of energy in the form of a photon. This concept of quantized energy levels and transitions is a fundamental aspect of the Bohr model and laid the groundwork for the development of quantum mechanics.
  • Describe how the principal quantum number relates to the stationary states in the Bohr model.
    • In the Bohr model, the principal quantum number, denoted as $n$, is a positive integer that represents the specific energy level or shell that an electron occupies within the atom. Each value of $n$ corresponds to a unique stationary state, with $n=1$ being the lowest energy level (the ground state) and higher values of $n$ representing progressively higher energy levels. The energy of a stationary state is inversely proportional to the square of the principal quantum number, $E = -13.6 \mathrm{eV} / n^2$. This relationship between the principal quantum number and the energy of the stationary states is a key feature of the Bohr model and is essential for understanding the behavior of electrons within an atom.
  • Analyze the role of stationary states in the transition of electrons between energy levels and the emission or absorption of photons.
    • Stationary states are central to the Bohr model's explanation of how electrons transition between energy levels and the associated emission or absorption of photons. According to the model, electrons can only exist in specific, discrete stationary states, each with a unique energy level. When an electron transitions from a higher energy stationary state to a lower energy stationary state, it releases the energy difference in the form of a photon with a specific wavelength or frequency. Conversely, when an electron absorbs a photon with the appropriate energy, it can be promoted to a higher energy stationary state. This quantized nature of electron transitions and photon emission/absorption is a fundamental aspect of the Bohr model and is a key step in understanding the behavior of atoms and the nature of light-matter interactions.