Title: To understand how the emission spectrum of hydrogen demonstrates the quantized nature of energy
1Objectives
- To understand how the emission spectrum of
hydrogen demonstrates the quantized nature of
energy - To learn about Bohrs model of the hydrogen atom
- To understand how the electrons position is
represented in the wave mechanical model
2A. The Energy Levels of Hydrogen
- Only certain types of photons are produced when
excited Hydrogen atoms release energy. Why?
3A. The Energy Levels of Hydrogen
- Atomic states
- Excited state atom with excess energy
- Ground state atom in the lowest possible state
- When an H atom absorbs energy from an outside
source it enters an excited state.
4A. The Energy Levels of Hydrogen
- Energy in the photon corresponds to the energy
used by the atom to get to the excited state.
5A. The Energy Levels of Hydrogen
- Only certain types of photons are produced when H
atoms release energy. Why?
6A. The Energy Levels of Hydrogen
- Since only certain energy changes occur the H
atom must contain discrete energy levels.
7B. The Niels Bohr Model of the Atom (1913-1915)
- Bohrs model of the atom
- Quantized energy levels
- Electron moves in a circular orbit
- Electrons jump between levels by absorbing or
emitting photons of a particular wavelength
Able to mathematically explain the emission
spectrum of Hydrogen (compare with Rutherford)
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9B. The Bohr Model of the Atom
- Bohrs model of the atom was not totally correct.
- Had difficulties with spectra of larger atoms
- Electrons do not move in a circular orbit and
dont seem to behave like discrete particles all
the time
Maybe small particles, such as electrons, can
also behave like waves having a dual nature (just
like photons)?
10C. The Wave Mechanical Model of the Atom (de
Broglie and Schroedinger mid-1920s)
- Orbitals
- Nothing like orbits
- Probability of finding the electron within a
certain space