Tuesday, September 18- TEST DAY
Turn in your Ch. 3 /4 Study Guide to the metal shelf (make
sure NAME on it!)
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Take out a sheet of paper, write name, date, and title
“Chapter ¾ Exam”
You will need a calculator and periodic table
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When you finish, begin completing Chapter 5 Vocab.
Wednesday, September 19
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Do not write down:
1. How many significant figures are in 90.00056?
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2. What is the scientific notation for 3987.3?
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3. What is the scientific notation of 000.047?
Graphic Organizer:
Using the vocabulary words posted on
the wall, you and your partner (s) are to
create a graphic organizer to summarize
and show the relationship between the
terms in Chapter 3 and 4
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Chapter 3:
1-10
11-18
•
•
•
•
Chapter 4:
1-9
15-20
21-26
Thursday, September 20
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Take out one piece of paper, title it “Periodic Law”
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1. What is the purpose of the periodic table?
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2. What model did Bohr suggest?
Friday, September 21
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Pick up one Chemistry Textbook
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Take out your notes from yesterday (with the table)
Periodic Table: What’s the trend?
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Think about your closet or music collection.
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How do you organize your possessions?
Bohr Model
Electrons in each shell:
2n²
2, 8, 8, 18, 18 32, 32
Niels Bohr in 1913, depicts the atom as a small,
positively charged nucleus surrounded by
electrons that travel in circular orbits around the
nucleus—similar in structure to the solar system,
but with electrostatic forces providing attraction,
rather than gravity.
Building your element
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In pairs, you will be assigned an element card.
On copy paper, draw the atomic model of your element
(make 3 COPIES).
DO NOT write the name of your element on the front.
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Under the model, copy the following in the identified color:
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Atomic Mass (green)
Atomic radii (blue)
Electronegativity (red)
Ionization Energy (black)
Find a Pattern
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Class will be divided into 2 groups.
Each group is to arrange the element cards in an
arrangement that makes sense to them
You MAY NOT use your periodic table.
Must take into account all properties, not just atomic
model
What’s the trend?
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Three groups will use the periodic table to organize the cards.
Tape the cards to the paper in the appropriate order (account for
energy levels)
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Group 1: Atomic Radius
Group 2: Electronegativity
Group 3: Ionization Energy
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Use a textbook (Ch. 5) to determine what your property means

Find a trend with your election configuration and your property.
Be able to explain to class.
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Periodic Law

Read Chapter 5, Section 1-2
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Take notes on sheet of paper as you read.
Monday, September 25

Take out your notes (with chart) from Friday

Chapter 5 Vocab Words due Tuesday (homework grade)
Copy the table in your notes
Definition
Atomic Radius
Electronegativity
Ionization Energy
Picture
Trend
Alternate Periodic Tables
Atomic Radius (Green)

measure of the size of its
atoms, usually the mean or
typical distance from the
nucleus to the boundary of
the surrounding cloud of
electrons
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Radius:
Trend:

What is the trend of atomic radius?
Increasing
Increasing
Electronegativity (red)
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describes the tendency of an atom to attract electrons
towards itself.
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What is the trend of electronegativity?
Ionization Energy (black)
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The energy required to remove one electron from a neutral
atom of an element
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What is the trend of ionization energy?
NOBILITY
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Stable/ unreactive.
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Which elements are most stable?
Periodic Law

Using the new periodic table, draw arrows and label the
new trends in the properties of elements on the periodic
table
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Atomic radii (blue)
Electronegativity (red)
Ionization Energy (black)
The Periodic Law
History of the Periodic Table
Mendeleev and Chemical Periodicity

Dmitri Mendeleev noticed that when the elements were
arranged in order of increasing atomic mass, certain
similarities in their chemical properties appeared at regular
intervals
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Repeating patterns = periodic

Mendeleev created a table in which elements with similar
properties were grouped together—a periodic table of the
elements
History of the Periodic Table

Mendeleev and Chemical Periodicity
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After Mendeleev placed all the known elements in his
periodic table, several empty spaces were left

In 1871 Mendeleev predicted the existence and properties
of elements that would fill three of the spaces
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By 1886, all three of these elements had
been discovered (Scandium, Gallium, Germanium)
Moseley and the Periodic Law
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In 1911, the English scientist Henry Moseley
discovered that the elements fit into patterns
better when they were arranged according to
atomic number, rather than atomic weight
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The Periodic Law states that the physical and
chemical properties of the elements are
periodic functions of their atomic numbers
History of the Periodic Table

Periodicity of Atomic Numbers
History of the Periodic Table

The Modern Periodic Table
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The Periodic Table is an arrangement of the elements in order of
their atomic numbers so that elements with similar properties fall in
the same column, or group