Section 5-1 (New Stuff) The Quantum Mechanical Model and Atomic Orbitals
Read over “The Quantum Mechanical Model” on page 130.
Atomic Orbitals (Pages 131-132)
______________________ is often thought of as a region of space in which there is a high probability of finding an electron.
The __________________ levels of electrons in the quantum mechanical model are labeled by the principal quantum number (n).
The principal quantum numbers are assigned values of ________________________.
For each principal energy level, there may be several ______________ with different shapes and at different ______________________ levels.
Each energy sublevel corresponds to an orbital of a different ____________________, which describes where the electrons are likely to be found.
S- orbitals are ________________________ in shape. P- orbitals are ______________________-shaped.
In the S-orbital, the probability of finding an electron at a given distance from the nucleus does not depend on _______________________________.
________________ kinds of P-orbitals have different orientations in space.
Four out of five D-orbitals have a _____________________ shape. The other orbital is called the
___________ orbital.
The principal quantum number always equals the number of _______________ within that principal energy level.
The maximum number of electrons that can occupy a principal energy level is given by the formula
_____________, where n is the principal quantum number.
Complete the following table (5.1)
Summary of Principal Energy Levels, Sublevels, and Orbitals
Principal Energy Level n=1 n=2 n=3 n=4
Number of sublevels Type of Sublevels

Using Table 5.1 answer the following questions:
1. How many sublevels are in level 5? Level 6? Level 7?
2. What are the types of sublevels in level 5?
3. What is the mathematical relationship between type (s, p, d, f, g, and so on) and number of orbitals?
4. How many orbitals relate to level 1? Level 2? Level 3? Level 4?
5. What is the pattern?
6. How many orbitals would you expect to relate to level 7?
Complete the following table:
Maximum Number of Electrons (Table 5.2)
Energy level n
1
Maximum Number of electrons
2
3
4
Answer #7 on page 132.
Section 5-2 Electron Arrangement in Atoms (Page 133)
The ways in which electrons are arranged in various orbitals around the nuclei of atoms are called
_____________________________________.
According to the _______________________, electrons occupy the orbitals of lowest energy first.
According to the _______________________________, an atomic orbital may describe at most two electrons.
To occupy the same orbital, two electrons must have ____________________ spins; that is, the electron spins must be _______________________. The spin may be thought of a
_____________________________________. An orbital containing paired electrons is written as
_______________________
__________________________ states that electrons occupy orbital of the same energy in a way that makes the number of electrons with the same spin direction as large as possible.
The shorthand method for drawing electron configurations of an atom involves writing the energy level and the _____________________ for every sublevel occupied by an electron. You indicate the number of electrons occupying that sublevel with a ________________________.
The sum of the superscripts equals the number of _____________________ in the atom.

When the configurations are written, the _____________ within the same principal energy level are written together.
Examples of exceptions to the Aufbau principle are ___________________ and __________________.
Some actual electron configurations differ from those assigned using the aufbau principle because
______________________ sublevels are not as stable as filled sublevels, but they are more stable than other configurations.
Examples: Write the electron configurations for the following atoms: phosphorous, neon, and nitogen.
Example: Write the electron configuration for sulfur. How many unpaired electrons does it have?
Something that might be useful is the Diagonal Rule: n=1 n=2 n=3 n=4 n=5 n=6
1s
2s
3s
4s
5s
6s
2p
3p
4p
5p
6p
3d
4d
5d
6d
4f
5f
6f n=7 n=8
7s
8s
7p
8p
Assignment: Page 135 Practice Problems #8 and #9