CHEMISTRY TOPIC SUMMARY
Name: ________________________
Block: ________
Date: _______________
Topic D: Chemical Foundations
Purple Packet
Textbook Reference
Pages 29-42
Chapter 3
Purpose
All matter is made from atoms and all matter can be broken down chemically into elements. Our
understanding of the elements has evolved through time with several important scientists making major
contributions to our current understanding.
In this Topic, we will study the elements, the history of the atom, and the modern concept of the atom.
We will also understand how an element can exist as different isotopes and as an ion.
Schedule
A and B
9/26 and
9/29
Due
 Be ready for
Elements 2 Quiz
9/30 and
10/1
 Worksheet 1
(pages 35-36)
10/2 and
10/3
 Worksheet 2
(pages 39-40)
10/6 and
10/7
 Foundations
Review (pages
41-42)
 Vision Writing
Assignment
Vocabulary
atom
atomic mass
atomic number
proton
neutron
electron
ion
In-Class
 Elements 2 Quiz
 Chem Foundations Notes
 Atomic Structure and Ion
Worksheets
 Ions, Radioactivity, and
Average Atomic Mass
 Average Atomic Mass
Worksheet
 Radioactive Isotopes Lab
 Review
HW Assignments
 Worksheet 1
(pages 35 – 36)
 Vision Writing
Assignment
 Worksheet 2
(pages 39-40)
 Foundations
Review (pages
41-42)
 Chemical Foundations Test  Begin Readings
for Modern
Atomic Theory
cation/anion
average atomic mass
isotope
half-life
α (alpha) radiation
β (beta) radiation
γ (gamma) radiation
Democritus
Dalton
Thomson
Millikan
Rutherford
Bohr
By the end of these Topics, you should be able to demonstrate proficiency in the following areas:
Essential Understandings
The concepts developed in this standard include the following:

The atomic number of an element is the same as the number of protons. In a neutral atom, the number of
electrons is the same as the number of protons. All atoms of an element have the same number of protons.

The average atomic mass for each element is the weighted average of that element’s naturally occurring
isotopes.

The mass number of an element is the sum of the number of protons and neutrons. It is different for each
element’s isotopes.

An isotope is an atom that has the same number of protons as another atom of the same element but has a
different number of neutrons. Some isotopes are radioactive; many are not.

Half-life is the length of time required for half of a given sample of a radioactive isotope to decay.

Electrons have little mass and a negative (–) charge. They are located in electron clouds or probability
clouds outside the nucleus.

Protons have a positive (+) charge. Neutrons have no charge. Protons and neutrons are located in the
nucleus of the atom and comprise most of its mass. Quarks are also located in the nucleus of the atom.
Knowledge, and Skills
In order to meet this standard, it is expected that students will

determine the atomic number, atomic mass, the number of protons, and the number of electrons of any
atom of a particular element using a periodic table.

determine the number of neutrons in an isotope given its mass number.

perform calculations to determine the “weighted” average atomic mass.

perform calculations involving the half-life of a radioactive substance.

differentiate between alpha, beta, and gamma radiation with respect to penetrating power, shielding, and
composition.

differentiate between the major atom components (proton, neutron and electron) in terms of location, size,
and charge.

identify key contributions of principal scientists including: Democritus, Dalton, Thomson, Rutherford,
Millikan, Bohr, Mendeleev

differentiate between the historical and quantum models of the atom.