Chapter 11: Modern Atomic Theory
Purpose
The arrangement of an atom’s valence electrons plays a role in its chemical properties.
The periodic table is a valuable tool for understanding the relationships between and properties of elements.
The placement of elements on the periodic table is based on both the properties and atomic number of the
elements. These properties can be explained by atomic structure, including electron configuration.
A and B
10/11 and 10/15
In-Class
 Chapter 11 Notes
 Talk about Chapter 11 Outline
 Finish Chapter 11 Notes
10/16 PSAT
 Practice lighting Bunsen
DURING PD1&2
burners
10/21 and 10/22
 Go over Chapter 11 Wk #1
 Periodic Table Lab
10/23 and 10/24
 Combined Element Quiz
 Go over Chapter 11 Wk #2
 Flame Test Lab*
10/25 and 10/28
 Go over Chapter 11 Review
 Chapter 11 Test
* This lab requires appropriate lab attire!!
10/17 and 10/18
HW Assignments
 Make an outline of
Chapter 11 Sections 1-8
 Element Quiz on 10/23 for
B Day or 10/24 for A Day
 Chapter 11 Worksheet #1
 Chapter 11 Worksheet #2
 Chapter 11 Review
 Study for Chapter 11 Test
**PSAT is on 10/16
Vocabulary
wavelength
frequency
speed of light
excited state
ground state
orbital
sublevels
electron configuration
valence electrons
kernel (core) electrons
Aufbau Principle
Hund’s Rule
Pauli Exclusion principle
Mendeleev
Moseley
group/family
period
alkali metal
alkaline earth metal
transition metals
halogens
noble gas
atomic radius
Ionization energy
By the end of this Topic, you should be able to demonstrate proficiency in the following areas:
Essential Understandings

Electron configuration is the arrangement of electrons around the nucleus of an atom based on their
energy level.

Electrons are added one at a time to the lowest energy levels first (Aufbau Principle). Electrons occupy
equal-energy orbitals so that a maximum number of unpaired electrons results (Hund’s Rule).
 Energy levels are designated 1–7. Orbitals are designated s, p, d, and f according to their shapes and
relate to the regions of the Periodic Table. An orbital can hold a maximum of two electrons (Pauli
Exclusion Principle).
 Atoms can gain, lose, or share electrons within the outer energy level.
 Discoveries and insights related to the atom’s structure have changed the model of the atom over time.
Historical models have included solid sphere, plum pudding, nuclear, and planetary models. The modern
atomic theory is called the quantum mechanical model.
 The periodic table is arranged in order of increasing atomic numbers.
 The names of groups and periods on the periodic chart are alkali metals, alkaline earth metals, transition
metals, halogens, and noble gases.
 Periods and groups are named by numbering columns and rows. Horizontal rows called periods have
predictable properties based on an increasing number of electrons in the outer energy levels. Vertical
columns called groups or families have similar properties because of their similar valence electron
configurations.
 The Periodic Law states that when elements are arranged in order of increasing atomic numbers, their
physical and chemical properties show a periodic pattern.
 Periodicity is regularly repeating patterns or trends in the chemical and physical properties of the
elements arranged in the periodic table.
 Atomic radius is the measure of the distance between radii of two identical atoms of an element. Atomic
radius decreases from left to right and increases from top to bottom within given groups.
 Shielding effect is constant within a given period and increases within given groups from top to bottom.
 Ionization energy is the energy required to remove the most loosely held electron from a neutral atom.
Ionization energies generally increase from left to right and decrease from top to bottom of a given
group.
Knowledge, and Skills

determine the number of valence electrons and from an element’s electron configuration.

write the electron configuration for elements of the periodic table.

differentiate between the historical and quantum models of the atom.


identify key contributions of principal scientists : Bohr, Planck, Heisenberg, de Broglie, Mendeleev, and
Moseley
distinguish between a group and a period.

identify key groups, periods, and regions of elements on the periodic table.

identify and explain trends in the periodic table as they relate to ionization energy, shielding effect, and
relative sizes.

compare an element’s reactivity to the reactivity of other elements in the table.

relate the position of an element on the periodic table to its electron configuration.
SOL Standards
CH.2 The student will investigate and understand that the placement of elements on the periodic table is a
function of their atomic structure. The periodic table is a tool used for the investigations of
d) families or groups;
e) periods;
f) trends including atomic radii, shielding effect, and ionization energy;
g) electron configurations, valence electrons, and oxidation numbers;
i)historical and quantum models