1. The Development of A New Atomic Model
Ch. 4.1

2. Properties of Light Acts like a wave
Electromagnetic radiation-wavelike energy traveling through space
X-Rays, ultraviolet light, infrared light, radio waves, etc
Electromagnetic Spectrum- organized list of all forms of electromagnetic radiation
All forms travel 3.00 x 108 m/s in a vacuum

3. Properties of Light
Wavelength
Frequency λ
Distance from crest to crest(or tough to trough) of corresponding waves
SI Unit: m, cm, or nm ν
# of waves that pass a given point in a specific time
SI Unit: Hz

4. Photoelectric Effect
Emission of electrons from a metal when light shines on the metal

5. Light as a Particle Quanta Photon
Quantum of energy is the minimum amount of energy that can be lost or gained by an atom
E- energy, J
h- Plancks Constant
6.626 x Js
v- frequency, s-1
Photon
Particle of electromagnetic radiation having zero mass and carrying a quantum energy

6. The Hydrogen-Atom Line Emission Spectrum
Ground State
Excited State
Lowest energy state of an atom
Atom has a higher potential energy than it does in ground state
Gives off light
Moving from excited back to ground state

7. The Hydrogen-Atom Line Emission Spectrum
Continuous Spectrum
Narrow beam of light, when passing through a prism
Emission of a continuous range of frequencies of electromagnetic radiation

8. Bohr’s Model of the Hydrogen Atom
Emission
Electron falls to a lower energy level
Photon is emitted
Absorption
Electron jumps from lower to higher energy level
Energy must be added

9. The Quantum Model of the Atom
Ch 4.2

10. Electrons as Waves
Diffraction
Interference
Bending of a wave as it passes through a small object
Waves overlap
Different areas have
Reduced energy
Increased energy

11. Heisenberg Principle
It is impossible to determine simultaneously both the position and the velocity of an electron of any other particle

12. Schrodinger Wave Equation
Quantum Theory
Describes mathematically the wave properties of electrons and other very small particles
Gives the probability of finding an electron in a given orbital
3 dimensional region around the nucleus that indicates the probable location of an electron

13. Atomic Orbital's and Quantum Numbers
Specifies the properties of atomic orbital's and the properties of electrons in orbital's
1st 3 Numbers
Indicate main energy level, shape and orientation of orbital
4th Number
“Spin” number describes the fundamental state of the electron that occupies the orbital

14. Atomic Orbital's and Quantum Numbers
Principle Quantum Number
Symbol- n
Indicates main energy level occupied by electron
Positive integers only
1,2,3, etc
As n increases, distance from nucleus increases
Electrons can have the same value
Same shell
Total orbital's in a shell(main energy level n2

15. Atomic Orbital's and Quantum Numbers
Angular Momentum Quantum Number
Sublevels
Orbital's of different shapes exist for a given value of n
Symbol- l
Indicates the shape of the orbital
Value
n-1; can be zero or positive integers

16. Atomic Orbital's and Quantum Numbers
Angular Momentum Quantum Number
s orbital
Spherical
p orbital
Dumbbell shape
d & f orbital's
More complex
n=1
S orbital
n=2
s & p orbitals
n=3
s, p, & d orbitals
n=4
s, p, d & f orbitals

17. Atomic Orbital's and Quantum Numbers
Magnetic Quantum Number
Symbol- m
Indicates the orientation of an orbital around the nucleus
Value
Whole numbers, including zero; -l to +l

18. Atomic Orbital's and Quantum Numbers
Spin Quantum Number
Only 2 Values
+1/2 and -1/2
Indicates the 2 spin states of an electron in an orbital
Single Orbit
Max of 2 electrons
Must have opposite spin states

19. Electron Configuration
Ch 4.3

20. Electron Configuration
Arrangement of electrons in an atom
Unique for each element
Ground State Electron Configuration
Lowest energy arrangement of electrons for each element

22. Rules for Electron Configuration
Aufbau Principle
Electrons occupy the lowest energy orbital that can receive it

24. Rules for Electron Configuration
Pauli Exclusion Principle
No two electrons in the same atom can have the same set of four quantum numbers
Arrows represent different spin states

25. Rules for Electron Configuration
Hund’s Rule
Orbital's of equal energy are each occupies by one electron before any orbital is occupied by a second electrons
All electrons in singly occupied orbital's must have the same spin state

26. Representing Electron Configurations
Orbital Notation
Electron Configuration Notation
Unoccupied orbital
___
Orbital with 1 electron
Orbital with 2 electrons
Quantum # and Sublevel underneath
Eliminates lines and arrows
Uses superscripts
1s22s22p6

27. Practice pg 113

28. 2nd Period Elements Highest Occupied Energy Level
Electron contained main energy level with the highest principle quantum number
Inner Shell Electrons
Electrons no in the highest occupied energy level

29. 3rd Period Elements Shorthand Notation Noble Gas Configuration
1st 10 electrons in an atom have the same configuration as Neon
Noble Gas Configuration
Outer main energy level occupied by 8 electrons (most cases)

30. 4th & 5th Period Elements

31. Practice pg 120

32. Practice pg 121

33. Practice pg 122