Lecture Notes on Light and the Hydrogen Emission Spectrum

Introduction to Light and Spectrum

• Light through a Prism
  • White light passed through a prism is refracted into a rainbow spectrum.
  • The spectrum is continuous, showing all frequencies of visible light.

Hydrogen Emission Spectrum

• Hydrogen Gas Lamp Experiment
  • Energy is passed through hydrogen atoms, emitting light.
  • Light passed through a prism shows only specific frequencies (line spectrum).
  • Line spectrum shows specific frequencies, not continuous.

Understanding the Hydrogen Atom

• Hydrogen Atom Model
  • Nucleus at the center, rings represent energy levels.
  • Ground state: electron in the lowest energy level.
  • Excited state: electron absorbs energy, jumps to a higher level.
  • Specific frequency of energy absorbed for transitions.

Electron Transitions and Emission

• Energy Absorption and Release
  • Specific energy absorbed for electron to jump up.
  • Energy released when electron drops back down.
  • Multiple energy levels lead to various transitions.

Hydrogen Emission Spectrum Analysis

• Emission Spectrum Lines
  • Lines represent electron transitions to the second energy level.
  • Four lines: red, green, blue, violet.
  • Red line: transition from n=3 to n=2.
  • Green line: transition from n=4 to n=2.
  • Blue line: transition from n=5 to n=2.
  • Violet line: transition from n=6 to n=2.

Bohr Model and Energy Levels

• Energy Level Convergence
  • Lines in spectrum converge as energy increases.
  • Suggests energy levels in atom converge at higher energies.
  • Edge of atom reached when energy levels are effectively the same.

Emissions Beyond Visible Spectrum

• Beyond Visible Light
  • Drops to n=1 seen in UV spectrum (more energy released).
  • Drops to n=3 seen in Infrared spectrum (less energy released).
  • Convergence observed in UV and Infrared spectra as well.

Summary of Key Points

• Emission Spectra
  • Produced by electrons dropping to lower energy levels.
  • Hydrogen spectrum indicates discrete energy levels.
  • Visible lines from drops to n=2; UV from n=1; Infrared from n=3.

These notes cover the main ideas and concepts discussed in the lecture about light and the hydrogen emission spectrum, providing a clear understanding of the topic.