1. Matter is a Wave Does not apply to large objects
Things bigger than an atom
A baseball has a wavelength of about m when moving 30 m/s
An electron at the same speed has a wavelength of 10-3 cm
Big enough to measure.

2. The Bohr Model
Electrons travel in discrete orbits around the atom's nucleus.
The chemical properties of the element are determined by the number of electrons in the outer orbits.

3. Bohr’s Theory Continued
Electrons drop from a higher-energy orbit to a lower one, emitting a photon (light quantum) of discrete energy (this became the basis for quantum theory).
Bohr won a Nobel Prize in 1922 for this work.

4. the electron absorbs energy as it moves up a level
as it falls down a energy level it emits energy in the form of light (the packet of energy is called a photon or quantum)

5. } Bohr’s Model Fifth Fourth Increasing energy Third Second First
Further away from the nucleus means more energy.
There is no “in between” energy
Energy Levels
Fourth
Third
Increasing energy
Second
First
Nucleus

6. The Quantum Mechanical Model
The Bohr model is accurate only for one- electron systems such as the hydrogen atom
The energy calculations were not accurate for atoms with multiple electrons.
The Quantum Model was developed to help answer these questions.

7. The Quantum Mechanical Model
Energy is quantized. It comes in chunks.
A quanta is the amount of energy needed to move from one energy level to another.
Since the energy of an atom is never “in between” there must be a quantum leap in energy.
Schrodinger derived an equation that described the energy and position of the electrons in an atom

8. Heisenberg Uncertainty Principle
It is impossible to know exactly the speed and velocity of a particle.
The better we know one, the less we know the other.
The act of measuring changes the properties.

9. After Before Photon changes wavelength Photon
Electron Changes velocity
Moving Electron

10. The Quantum Mechanical Model
Has energy levels for electrons.
Orbits are not circular.
It can only tell us the probability of finding an electron a certain distance from the nucleus.

11. Atomic Orbitals
Principal Quantum Number (n) = the energy level of the electron.
Within each energy level the complex math of Schrodinger’s equation describes several shapes.
These are called atomic orbitals
Regions where there is a high probability of finding an electron.

12. S orbitals 1 s orbital for every energy level Spherical shaped
Each s orbital can
hold 2 electrons
Called the 1s, 2s, 3s, etc.. orbitals.

13. P orbitals Start at the second energy level 3 different directions
3 different shapes
Each can hold 2 electrons

14. D orbitals Start at the third energy level 5 different shapes
Each can hold 2 electrons

15. F orbitals Start at the fourth energy level
Have seven different shapes
2 electrons per shape

16. F orbitals

17. By Energy Level
Any more than the fourth and not all the orbitals will fill up.
You simply run out of electrons
The orbitals do not fill up in a neat order.
The energy levels overlap
Lowest energy fill first.