CHEMISTRY IN CONTEXT
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LAB 9: ATOMIC MODELING OF OCTET RULE, PAGE 1
CYCLE 4
Atomic Modeling
The Octet Rule
PRE-LAB DISCUSSION:
The elements on the periodic table are arranged into rows and columns based on the way that
their electrons configure. As we discussed before, many columns are also families. Columns
indicate valence or how many electrons are in the outer orbital of the element. Rows are periods
indicate how many orbitals the atom will have.
Today, you will be using pipe cleaners and colored beads to create models of the Octet Rule.
The Octet Rule says that the first orbital of any atoms can ONLY hold two electrons. The next
two orbitals can each hold 8 electrons. You MUST fill an orbital BEFORE you move onto the
next one. So, for example, in helium, BOTH of its electrons are in the first orbital. Helium is a
noble gas, and the noble gases are inert or nonreactive because they have FULL orbitals. Every
atom chemically reacts with other things to have FULL orbitals. Keep that in mind!!!
APPARATUS/MATERIALS:
3 cups
20 beads of color #1
20 beads of color #2
20 beads of color #3
10 long pipe cleaners (select either black or white for ALL pipe cleaners)
4 pre-cut short pipe cleaner (either black or white)
PROCEDURE:
1)
Assign each bead color to a different subatomic particle and record your color
decisions in the space below:
a)
electrons are
(Color #1)
b)
2)
3)
4)
protons are
(Color #2)
c)
neutrons are
(Color #3)
Take two long pipe cleaners and attach them into one long strand. This will be the
first or closest orbital of your atomic modeling today.
Take three long pipe cleaners and attach them into one long strand. This will be the
second orbital of your atomic modeling today.
Remove 4 beads of color #3 from your cup and remove 3 beads of color #2.
Alternate these colors as you string them onto the short pipe cleaner. Then, bend the
ends of the pipe cleaner to close the loop and hold the beads together.
CHEMISTRY IN CONTEXT
NAME
LAB 9: ATOMIC MODELING OF OCTET RULE, PAGE 2
CYCLE 4
5)
6)
7)
8)
9)
10)
11)
12)
Remove 2 beads of color #1 from your cup and string them onto the pipe cleaner
strand for orbital #1 (the first orbital). Close the loop by twisting the ends of the
strand of pipe cleaners together.
Remove 1 bead of color #1 from your cup and string it onto the pipe cleaner strand
for orbital #2 (the second orbital). Close the loop by twisting the ends of the strand of
pipe cleaners together.
On your desktop, arrange the three parts that you have created to model an atom.
Take a look at your periodic table (the big one OR the one on the side of the cups).
Which element did you just model? Record the element’s name and sketch a picture
of its model in the Data/Observation section.
Now, use the remainder of your pipe cleaners to create a model for fluorine.
Remember that the first orbital MUST fill with two electrons before proceeding to the
second orbital.
Sit the models for your two atoms side by side. Lithium belongs to the alkali metals
family and fluorine belongs to the halogen family. These two elements LOVE to
come together and form the chemical compound lithium fluoride (LiF). Reread the
last two sentences in the second paragraph of the Prelab/Discussion. If metals and
non-metals can give up or take in electrons to combine chemically and have FULL
orbitals, how might lithium and fluorine work together to accomplish this task?
Record the response to this question in the Analysis section (#1).
Dismantle your atomic models.
Create an atomic model for neon. Sketch a picture of your Neon model in the
Data/Observation section. Take a look at neon’s atomic structure, specifically, its
electrons and orbitals. Why does neon NOT react with any other elements? Record
the response to this question in the Analysis section (#2).
Break down all of your models and return your supplies to their appropriate
containers.
DATA/OBSERVATIONS:
Element Name:
Sketch:
CHEMISTRY IN CONTEXT
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LAB 9: ATOMIC MODELING OF OCTET RULE, PAGE 3
CYCLE 4
DATA/OBSERVATIONS (CONT.):
Element Name:
Fluorine
Sketch:
Element Name:
Neon
Sketch:
ANALYSIS:
1)
If metals and non-metals can give up or take in electrons to combine chemically and have
FULL orbitals, how might lithium and fluorine work together to accomplish this task?
CHEMISTRY IN CONTEXT
NAME
LAB 9: ATOMIC MODELING OF OCTET RULE, PAGE 4
CYCLE 4
2)
Why does neon NOT react with any other elements?
3)
To FILL their outer shells, which families of elements are most likely to react with each
other? Why?
CHEMISTRY IN CONTEXT
LAB 5: ATOMIC MODELING, PAGE 2
CYCLE 3
NAME
PROCEDURE:
1)
Use your cup to collect three different types of candy (OR three different colors of the
same candy).
2)
Identify each of the different candies as one of the following categories:
a) electrons
b) protons
c) neutrons
3)
Arrange the candies on the plate to model an atom with an atomic number between 1
and 8.
4)
Call your teacher over to show him or her your model.
5)
Repeat Step #3 for two additional elements.
DATA/OBSERVATIONS:
Sketch a picture of EACH of the atoms that you chose to model with the symbol for the atom
below it:
CHEMISTRY IN CONTEXT
LAB 5: ATOMIC MODELING, PAGE 3
CYCLE 3
NAME
ANALYSIS:
1)
If there are protons and neutrons in the nucleus and electrons in orbit around the nucleus,
which atom must this be? Label all parts.
2)
Atoms can have multiple orbitals/energy levels for the electrons. Take a look at the
following atom. If there are protons and neutrons in the nucleus and electrons in orbit around the
nucleus, which atom must this be?