|
|
|
|
| |
|
|
| |
| So what's
the big deal if I don't brush the way I should?
|
| |
| Objectives: |
 |
Students
will understand the destructive nature of
plaque acid in their mouths. |
|
Students
will use the scientific method for proving
a hypothesis. |
|
| |
| Materials: |
|
2 small
jars with lids |
|
Label |
|
Marker |
|
Pieces
of eggshell |
|
Water |
|
White
vinegar |
|
Science
journals |
|
Pencils |
|
| |
| Preparation: |
|
Assemble
materials |
|
| |
| Instructions:
|
| 1. |
Ask
students what they know about tooth decay. |
| 2. |
Explain
that you will be conducting a scientific experiment
today on what happens when teeth are not properly
cleaned and the acids produced by plaque attack
the teeth. |
| 3. |
Explain
that vinegar is a mild acid. If we do not
brush our teeth, plaque forms and gives off
acids very similar to vinegar. Also explain
that one of the materials that make up eggshells,
calcium, is also an important substance in
teeth. For the experiment, you will be using
eggshells to represent teeth, and vinegar
to represent the acids in plaque. The second
jar with eggshells in water is the control,
or something you will use to compare the findings
in the jar with vinegar. |
| 4. |
Place
several pieces of an eggshell into each of
the two glass jars and ask the students to
hypothesize, or make their best guess, at
what will happen when you put water in one
jar and vinegar in the other. |
| 5. |
Have
them record their ideas in their science journals. |
| 6. |
Now
fill enough water into one jar to cover the
eggshells and do the same with vinegar in
the other jar. Label and date the two jars.
|
| 7. |
Let
the students observe the contents of the two
jars and note anything they see. (Small bubble
will form on the eggshell in the vinegar -
this is a chemical reaction). |
| 8. |
Explain
that this is similar to what happens when
you eat. Acids in your mouth, much like the
acids in vinegar, react with the food and
start to break it down. Some acid is helpful
for us to digest our food but, unless we brush
and floss regularly, we could have too much
of it, which is harmful to our teeth. |
| 9. |
Ask
the students to come up with a hypothesis
of what will happen if you leave the vinegar
and eggshell in the jar for several days.
They should write this in their journals and
at the end of the experiment can check to
see if they guessed correctly. |
| 10. |
Observe
the changes that take place twice a day and
have the students record these in their science
journals. |
| 11. |
In
two or three days, the acids in the vinegar
will dissolve the eggshell. The eggshell in
the jar with water will remain unchanged.
Explain that the acids in the vinegar are
similar to the acids that attack the enamel
in our teeth. If teeth are not brushed and
flossed, the enamel can begin to dissolve
and allow cavities to form. |
|
|
|
|
|
|
|
|
|
|
