Quantum Mechanics

BOHR THEORY

• The elctron is a particle that must be in orbital in the atom
• Quantum Theory
• The electron is a cloud of negative charge or a wave function
• Orbitals are areas in 30 space where the electrons most probably are
• The energy of the electron is in its vibrational modes - like notes on a guitar string
• Photons are produced when high energy modes charge to lower energy modes

S ORBITALS
-Each orbital holds 2 electrons

P ORBITALS
- There are 3 suborbitals
- Each contains 2 electrons\

D ORBITALS
- There are 5 suborbitals
- each contain 2 electrons
- Total elctrons = 10

F ORBITALS
- There are 7 suborbitals
- Each contain 2 electrons
- Total electrons = 14

Bohr Model II

- Atoms are electrically neutral
- Two different models can be used to describe electron configuration

• Energy Level Model
• Bohr Model

-Electrons occupy shells which are divided into orbitals

• 2e in the first orbital
• 8e in the second (octet)
• 8e in the third (octet)

Bohr's Model

-Bohr (1920's)

•  Rutherford's model was inherently unstable - protons/electrons should attract each other
• Matter emits light when it is heated (blackbody radiation)
• Light travels as photons (particles of light) - waves + particles at the same time
• The energy photons carry depends on their wavelength - shorter the wavelength, the higher the energy

Seperate the white light into colours with a diffraction grating or prism

• Bohr based his model on the energy (light) emitted by difficult atoms
• Each atom has a specific spectra of light
• To explain this emission spectra, Bohr suggested that electrons occupy shells or orbital 

BOHR`S THEORY

• Electrons exist in orbitals
• When they absorb energy, they move to a higher orbital
• As they fall from a higher orbital to a lower one, they release energy as a proton of light

Examples: stars, lightning, aurora (northern lights), fireworks

Density and Graphing

DENSITY

• The density of an object is in it's mass divided by its volume
• And is usually expressed in kg/L, kg/m³, or g/cm³

GRAPHING

• All graphs must contain 5 important things:

1. Labelled axis
2. Appropriate scale
3. Title
4. Data Points
5. Line of best fit

• Three things can be done when working  with graphs

1. Read the graph
2. Find the slope (rise/run)
3. Find the area under the graph

THE NO-NO'S:

1. No squiggly lines!
2. Don't connect the dots "This isn't kindergarten!"