Part way through this semester I had to complete a short presentation in front of my class. This presentation had to be related to any grade in the Saskatchewan curriculum for science. I chose to do an experiment relating to the Grade 5 Curriculum. This experiment had a bit of magic in it when two “liquids” were combined.
Below is the lesson plan I used.
Dancing Spaghetti
Purpose: Allow the students to hypothesize what will happen
Allow students to observe a chemical change
Allow the students to develop explanations to explain what they observed
Allow the students to predict what was in the water and what the “mystery
liquid”/magic potion was in order to create the effect
Assess the ability of the students to consider the possible chemicals used in
the experiment without being told based on their observations
Entertain the students and get them excited about learning about chemical
changes through a hands-on experience
Through these actions I hope to teach the students about chemical changes by providing
them with the ability to take what they have previously learned about combining different substances and chemicals, the changes that occur, and helping the students make educated guesses about what else could be in the water.
Objectives and Indicators for Grade 5:
MC5.1 Investigate the characteristics and physical properties of materials in solid, liquid, and gaseous states of matter.
e. Pose questions related to the characteristics and physical properties of matter that are suitable for investigating using processes of science.
f. Observe and record characteristics and physical properties (e.g., colour, texture, mass, volume, hardness, flexibility, absorbency, strength, buoyancy, melting point, malleability, magnetism, and solubility) of different solids, liquids, and gases in their environment.
MC5.2 Investigate how reversible and non-reversible changes, including changes of state, alter materials.
f. Differentiate between changes to materials that occur rapidly (e.g., wood burning, explosives detonating, balloon popping, and glass breaking) and those that occur over extended periods (e.g., bicycle rusting, paint fading, and newspaper yellowing).
Materials:
O A tall, clear glass filled with water
O 3 pieces (each approximately 3 cm in length) of uncooked spaghetti
O 1 tablespoon of baking powder
O 4 tablespoons of vinegar (or a splash of vinegar- for a splash you may need a few small containers for the students)
Set up: Mix baking soda with water
Pour vinegar into smaller containers
Provide each table of students with a beaker, a small cup of vinegar, and a few
spaghetti noodles
Demonstration:
1. Have the water and baking soda pre-mixed. This is important in order to add to the excitement and mystery of the experiment as well as allowing the students to think creatively as to what was possibly added. The tall clear glass will be filled with the baking soda solution prior to the arrival of the students. Ask the pre questions at this point in time (see below for the questions).
2. Ask the students if they think the spaghetti will float or sink. Instruct the students to drop the pasta into the glass and observe what happens. The pasta should sink to the bottom.
3. Next explain to the students that to make the spaghetti dance in the glass it needs something special. It needs some “magic potion”. Add 4 tablespoons/a splash of vinegar to the baking soda and water. The mixture should fizz and bubble, but if it does not fizz or bubble add a bit more vinegar. Allow the students to observe what they have done. The pasta begins to float up and then down in the water and it appears as though the spaghetti is dancing!
4. Ask the students the remainder of the of the during questions. Ensure that the students have the opportunity to answer every question based on their personal observations at their table.
Possible prompts for the questions:
Explain that a chemical change formed and ask the students if they can
think of any reasons why it is a chemical change. Was a new substance formed (yes, a gas was produced) and what did we observe to show that a gas was produced (hear the fizzing, saw the bubbles on the spaghetti)? Does anyone know what kind of gas? Why was a gas produced? What is so special about baking soda and vinegar (introducing acids and bases may be too advanced but the students may be curious)?
Describe what is happening to the spaghetti pieces. I would anticipate an
answer that there are bubbles attached to it, but they disappear when it reaches the top, causing it to sink back down.
Explain to the students that the spaghetti will continue to dance as long as the vinegar is able to react with baking soda.
5. Ask the post questions. Allow the students to guess what could be in the water or what the magic potion was. Everything used can be found in a kitchen. Explain that the water had baking soda dissolved in it, which is why it looked like normal water, and that the magic potion was vinegar.
Explanation: When the spaghetti is added to the water solution it is expected to sink. This is because it is more dense and is heavier than what the water could support.
When the vinegar is added it is expected that the spaghetti will begin to float. If the spaghetti does not float add more vinegar. This is a chemical change that occurs between the vinegar and the baking soda that is dissolved in the water. This occurs because the two substances(a base and an acid) interact to produce Carbon Dioxide (CO2). The CO2 gas is visible in the solution as small bubbles that appear to attach to the spaghetti, causing it to rise to the top. When the bubbles reach the top of the glass it appears as though the bubbles are breaking causing the spaghetti to dip down again before having more bubbles attach, brining it back to the top of the glass.
Since the gas bubbles are less dense than the water, they float to the top. When they attach to the spaghetti they then cause the spaghetti to float up. This entire experiment relates to the chemical reaction that creates CO2 gas, which is less dense than the solution it is created in, and the spaghetti that is influenced by the density of the gas.
Safety: Do not put anything used in the science lab in your mouth
Do not have your face too close to the glass/beaker when adding substances
If anything happens to end up in a student’s eye, rinse immediately with water
Questions: Pre: Joke: How do you make a Kleenex dance? You put a little boogey in it.
Do any of you know how to make spaghetti dance?
What is in the small container?
How do you know?
What is in the big container?
How do you know?
What will happen when the noodles are added to the glass?
Will they sink or float? Why?
What could happen when you add the “magic potion” to the glass?
Any predictions? Why?
During: What happened to the spaghetti when it was added to the liquid?
Why did that happen?
What did you observe when you added the contents of the smaller
container?
Were there noises?
What did you see?
Did you smell anything?
Did we create a physical or chemical change?
What happened to the spaghetti pieces?
Did it rise and stay at the top?
Did you observe any changes to it?
Post: Do you think it was just water in the glass?
What could cause the mixture to bubble?
Why does the spaghetti continue to “dance”?
If the spaghetti sinks, what could we do to make it dance again?
This activity was great. Starting the lesson out with the riddle was a great start and got the students intrigued. I think that also having the baking soda and water premixed so it looked like water provided the mystery for the students and provided them with the opportunity to think beyond what they could see and hypothesize about what could be in the water. Overall I think my engagement activity went very well and it provided me with the confidence I need to be able to teach science in an elementary classroom.
does it matter what gas is used when the effect is produced?
ReplyDelete