Unit 2: Matter Lesson 7: The
Periodic Table (BellWork: IN)
Observe the Periodic Table on pgs. 154 and
155. The Periodic Table arranges elements
according to increasing atomic numbers
rather than atomic masses.
Are there any atomic numbers out of
numerical sequence? If so, which
elements?
Are the elements in order of increasing
atomic masses?
Unit 2: Matter
Lesson 7: The Periodic Table
(Elements)
• In the 1860s, scientists realized there are at least 60
different basic classifiable elements.
• Dmitri Mendeleev was the one who was able to
arrange the elements on cards by increasing atomic
mass and he is given credit to creating the periodic
table.
• Henry Moseley (1900s) then further worked on the
periodic table and arranged them by increasing atomic
number. This made it possible to arrange the different
elements by their similar properties.
Unit 2: Matter
Lesson 7: The Periodic Table
• The Periodic Table is a grid that informs us of each
element’s atomic number, chemical symbol, chemical
name, and average atomic mass.
• DRAW ONE CHEMICAL SQUARE HERE AND LABEL IT!
• Rows = Periods (physical and chemical properties
change from one end to the other)
• Columns = Groups (similar physical and chemical
properties like the same number of valence electrons)
• (Atomic Mass) = most stable radioactive
elements/isotopes
• Zigzag = metals (left) vs nonmetals (right)
Unit 2: Matter Lesson 7: The
Periodic Table (OUT)
What did you learn about the
Periodic Table that you did not know
before?
Activity: Make your own Periodic Table
Part 1 (pgs 154-155):
• Color metals, nonmetal, and
metalloids
• Draw in the zigzag line
• Label Periods and Groups
• Write down why the bottom
two rows are where they
are AND draw an arrow to
the area on the Periodic
Table where they belong.
Part 2 (pgs 158-159):
• In your table answer the
following:
1. Where are the most dense
elements?
2. Which element is the densest?
3. Which elements are the least
dense?
4. Where are the full set of valence
electrons?
5. Where are the smallest set of
valence electrons?
6. Where are the unreactive gases?
7. Where are the reactive gases?