1. Chemistry Chapter 4 Arrangement of Electrons in Atoms
electromagnetic radiation- a form of energy that exhibits wavelike behavior as it travel through space
wavelength ( λ )- the distance between corresponding points on adjacent waves
frequency ( f ) the number of waves that pass through a specific point in a specific time
hertz ( Hz )- a frequency of one wave per second

2. Speed of Electromagnetic Radiation
The speed ( c ) of all wavelengths of electromagnetic radiation = 3.0 x 108 m/s.
c = fλ
IF “c” is a constant, then wavelength varies inversely with the frequency of electromagnetic radiation.

3. Photoelectric Effect
photoelectric effect- the emission of electrons from a metal when light shines on that metal
quantum- the minimum amount of energy that can be gained or lost by an atom
photon- a quantum of light energy
ground state- the lowest energy state of an atom
excited state- a higher energy state

4. Spectra
line-emission spectrum- The specific colors (frequencies) of light emitted when an atom returns to the ground state from the excited state.
It can be seen when the light is separated by a prism and will give an element a specific spectrum.
continuous spectrum- the emission of a continuous range of frequencies of electromagnetic radiation

5. Section 2 The Quantum Model of the Atom
Heisenberg Uncertainty Principle- it is impossible to determine simultaneously both the position and the velocity of an electron
Quantum theory- describes mathematically the wave properties of electrons
orbital- a three-dimensional region around the nucleus that indicates the probable location of an electron
Each orbital can contain a maximum of 2 electrons.

6. Atomic Orbitals and Quantum Numbers
quantum numbers- specify the properties of atomic orbitals and the properties of the electrons in the orbitals
principal quantum number- indicates the main energy level occupied by an electron
the number of electrons possible per energy level = 2 n2 where n = energy level
angular momentum quantum number- indicates the shape of an orbital
s, p, d, & f
magnetic quantum number- indicates the orientation of an orbital around the nucleus of an atom
spin quantum number- indicates the two fundamental states of spin of an electron

7. Orbitals
There is a single “s” orbital per energy level for a maximum of 2 “s” electrons per level.
the energy level for “s” orbitals = the period number
There are 3 “p” orbitals per energy level for a maximum of 6 “p” electrons per level.
the energy level for “p” orbitals = the period number
There are 5 “d” orbitals per energy level for a maximum of 10 “d” electrons per level.
the energy level for “d” orbitals is the period number minus 1
There are 7 “f” orbitals per energy level for a maximum of 14 “f” electrons per level.
the energy level for “f” orbitals is the period number minus 2

8. Section 3 Electron Configurations
electron configuration- the arrangement of electrons in an atom
Rules governing electron configuration:
Aufbau principle- an electron occupies the lowest energy orbital that can receive it
Pauli exclusion principle- no two electrons in the same atom can have the same four quantum numbers
Hund’s rule- orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron

9. Electron Configuration Notation
ORBITAL NOTATION: See pg
ELECTRON-CONFIGURATION NOTATION:
See pg 113
[Ne] 3s23p4
Do Practice #1 & #2 on page 113.

10. Elements & Electron Configurations
1st period elements- see periodic table
2nd period elements
3rd period elements
noble-gas configuration- refers to an outer main energy level occupied by eight electrons ( ns2np6 in most cases)
4th period elements
5th period elements
Do Practice #1-4 on page 121.

11. Elements & Electron Configurations
Elements of the 6th and 7th periods contain “f” orbitals.
Do Practice #1 & 2 on page 122.
Do Section Review #5 on page 122.
Do Chapter review #33, 36, & 38 on pages
Review for Chapter 4 Test

12. Chapter 4 Test- (40 questions)
Know the meaning of the formula c = fλ .
Know the meaning of hertz, wavelength, photon, photoelectric effect, ground state, excited state.
Know how EMR travels through space.
Know how a line spectrum is produced.
Know what must happen for an electron to move between the ground and excited states.
Understand the Bohr model of atoms.
Know the definition of electron cloud, the quantum numbers, orbital.
Know how to calculate number of electrons per energy level.

13. Chapter 4 Test
Understand the differences in the energies of different orbital sublevels.
Know Aufbau principle, Hund’s rule, & Pauli exclusion principle.
Identify elements using their electron configuration notation.
Determine the electron configuration notation of elements.
Know the definition of a noble gas.
Write an electron configuration notation using an element’s orbital notation.
Identify an element using its orbital notation diagram.