1. Quantum Mechanical Model of the Atom
Chp 5.2

2. Bohr’s model failed to explain the spectrum for any other element other than Hydrogen.

3. De Broglie’s Observation: only certain numbers of wavelengths are allowed in a circular orbit of a fixed radius.
Conclusion: The electron's orbit has wave characteristics. Only certain wavelengths, frequencies, and energies are possible.
Electrons, like light, also have a wave/particle nature.

4. Particle/Electromagnetic-Wave Relationship

5. Werner Heisenberg’s Observation: it is impossible to take any measurement of a tiny object without disturbing the object.
Conclusion:
The Heisenberg Uncertainty Principle-it is fundamentally impossible to know precisely both the velocity and position of a particle at the same time. We can only know the probability of where an electron will be found outside of the nucleus.
= no effect
tiny electron
= change in position and velocity of electron

6. It is impossible to assign fixed paths for electrons like circular orbits in Bohr's model.

7. Erwin Schrodinger
Conclusion: His equation treats the electron as a wave.
Each solution is a wave function which predicts where the electron is most likely found in the atom.
The 3D space around the nucleus is called an atomic orbital. There is no definite boundary.

10. The atomic model in which electrons are treated as waves is the quantum mechanical model. Like Bohr's model, electrons have certain energy levels.

11. Quantum Numbers -specify properties of orbitals
principle quantum number (n), distance from nucleus
Ex: n=1, 2, ...7
sublevels, orbital types
Ex: s (sharp), p (principal), d (diffuse) and f(fundamental)
number of orbitals related to that shape.
Ex: s=1, p=3, d=5, f=7.
maximum number of orbitals in each energy level, n2
Ex: 1st=1, 2nd = 4, 3rd = 9, and 4th = 16