LaShawn S. Freeman
“The History of the Periodic Table of Elements”
Chemistry 511 – The Physical Basis of Chemistry
MISEP
Final Project
Title:
The History of the Periodic Table of Elements
Goals & Objectives:
Students will be able to describe the history of the Periodic Table of Elements.
Students will be able to interpret an element key.
Students will be able to explain how the Periodic Table of Elements is organized.
Pennsylvania State Standards:
3.4.7. A. Describe concepts about the structure and properties of matter.
~ Identify elements as basic building blocks of matter that cannot be broken
down chemically.
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Background Information
The Periodic Table was developed in an attempt to organize the elements, which
were discovered by scientists with the discovery of atoms. Early philosophers debated,
reasoned and discussed the concept of matter. What was it made of? They concluded that
you could take a piece of matter and continuously cut it into half again and again until you
would only have one particle left. They named this particle “the atom” which means
“cannot be divided”.
In the 1800’s scientists, called chemists, developed methods used in laboratories
that allowed them to take substances apart to figure out what they were made of; as well as
mix substances together to form new ones. This type of experimentation caused scientists
to discover that some substances could not be broken down into simpler substances.
Scientist called these substances elements. In the early 1900’s an English schoolteacher by
the name of John Dalton combined the idea of the element with the earlier idea of the atom.
He proposed the following; (1) Matter is made up of atoms, (2) atoms cannot be divided
into smaller pieces, (3) one type of element is made up of all of the same type of atoms, (4)
different elements are made up of different types of atoms.
In the 1830’s scientists had isolated and named 55 different elements. A scientist
by the name of Dmitri Mendeleev (1834-1907) developed the first version of the periodic
table of elements in 1869 in an attempt to organize the elements. In his table Mendeleev
arranged the atoms in order of increasing atomic mass onto cards. He placed elements that
had similar properties into groups. Because all of the elements were not known at this
time there were gaps in his groups. This excited other chemists to look for the missing
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elements. The discovery of the other three elements took about fifteen years which were
gallium, scandium, and germanium.
In the early twentieth century, an English physicist by the name of Henry
Moseley (1887-1915) realized that Mendeleev’s table could be improved by arranging the
table in order of increasing atomic number rather than atomic mass. This is due to a few
elements seeming to be out of place. Once Moseley completed the rearrangement of the
periodic table of elements it was clear how many elements were missing from the table.
Today there are one hundred fourteen known elements arranged on the table;
ninety-two are natural elements while twenty-two are synthetic. The elements are still
arranged according to their atomic number. Due to the similar characteristics that the
elements fall into the table can be sectioned off in a number of ways. If you travel vertically
along any column in the table you will come across groups (18 group’s total). Starting from
the first element in a group and working your way down you will notice that the atoms of
each element gets larger as you travel down the column. While traveling across the table
along horizontal rows are called periods (7 period’s total). When traveling across a period
from right to left the atom of each element starts off large and gets smaller as you move to
the left side of the table. The modern table also naturally groups the elements by metals,
non-metals and metalloids; which are non-metals that have a few metal-like properties.
These are just a few ways that the table has grouped the elements by arranging them
according to atomic number.
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Lesson #1(2days)
The Periodic Table of Elements
Anticipatory Set:
Ask students to discuss the following questions in a group and to record their answers.
Have students share their group responses with the class.

What are elements?

What are elements made of?

What are elements used for?
Objective:
Inform students that at the end of the lesson they will be able to:

Describe the history of the periodic table.

Interpret an element key

Explain how the periodic table is organized
Materials:

Glencoe Science Level Blue 2005 Edition ~ Text Book

Construction Paper

16 pieces of paper (about ½” by ½”) of mixed colors and shapes for each group
of students

Ruler

Loose Leaf Paper

Pencil/Pen

Chart Paper

Markers
Modeling:
Mini-Lab:
1) Students will use the ruler to make a grid, with four squares across
and four squares down, on sheet of construction paper.
2) Students will distinguish characteristics of the 16 pieces of paper.
3) Students will place a piece of paper in each square of their grid by
arranging the pieces on the grid so that each column contains pieces
that are similar.
4) Students will then rearrange each column so that within each column
they show a gradual change in the pieces appearance as the column
goes from top to bottom.
5) Students will answer the question “Describe how the properties
change in the rows across the grid and in the columns down the grid?”

Students will be informed that all of the elements are listed on the periodic table
of elements
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
Students will read, take notes and discuss pages #434-440 (Copy of Pages
included) of the Glencoe Science Text as a whole class. “The Periodic Table of
Elements” (*See notes at the end of lesson for summary)
Guided Practice:

Students will answer the following questions; each group will be assigned a
question to answer and report out to the class. (Place on chart paper)

Evaluate the elements in period 4 to show how the physical state
changes as the atomic number increases.

Describe where the metals, nonmetals and metalloids are located in
the periodic table.

How would the modern periodic table of elements be different if the
elements were arranged by average atomic mass instead of by atomic
number?

Classify each of the following elements as a metal, non-metal, or
metalloid: Fe, Li, B, Cl, Si, Na, and Ni.
Closure:

Student will review answers with whole class from guided practice.
Independent practice:

Students will create their own version of the modern periodic table of elements.
o
Students are encouraged to keep the basic format of the modern table
of elements while adding a touch of creativity on how it will be displayed
o
Students must create their table on a poster board.
*Note:
The information the students will obtain by reading the required text from the
Glencoe Science text book gives an overview of the periodic table of elements. The reading
begins by giving students a brief history of the table including information about how and
why it was created first by Dmitri Mendeleev and then improved upon by Henry Moseley;
who gave us the modern version of the table. The students will then continue to read
information as to the organization of the table gaining knowledge of; groups, periods,
transition elements, representative elements and inner transition elements. In the reading
students have a chance to see the table in an outline form with information on how the
table is presently divided. As well as a version of the table in its entirety with all of the
currently known elements listed.
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Reflection/Assessment
Project
Students will create a poster board representing any element from the periodic
table of elements.
Boards must include:
I.
an element key (including element name, atomic number, symbol &
atomic mass)
II.
a picture of the element
III.
a list of at least five uses of the element – can include pictures of the
element in use
IV.
a picture of the nuclear atomic structure of the element
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Bibliography Page
Glencoe, McGraw-Hill. (2005) Glencoe Science – Level Blue, Pgs. 434-440
Retrieved April 2008, from http://www.chemistry.co.nz/henry_moseley.htm
Retrieved April 2008, from http://www.chemcool.com/biography/moseley.htm
Retrieved April 2008, from http://www.chemistry.co.nz/mendeleev.htm
Retrieved April 2008, from
http://www.rsc.org/education/teachers/learnnet/periodictable/pre16/develop/mendele
ev.htm
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