Chemical Properties 3rd Grade Lesson 4

Boys and girls we are trying to figure out a mystery!

• Focus question: How can we change properties by adding water, iodine, red cabbage juice, and vinegar? (Have a discussion with the students and also make a connection to what they did the day before.) Today we are going to find out about our properties by our unknowns.

• Prediction: What reactions do you think we will have by adding these elements to the chemicals?

• Planning: The students will receive carton or cardboard with a paper that has five circles, labeled by the corresponding color that is labeled on the container that hold the mystery substances. The students will be handed the five mystery substances labeled orange, yellow, red, and blue. There is a spoon marked with the color that goes to the substance so the students do not cross contaminate. There will also be toothpicks for the students to use to mix and test the substances. On the piece of paper there will be a sixth circle divided into five different sections to place the correct substance with the colored labeled. The sixth circle will be the control circle, which the students will use to compare the other circles with. (Tell the students all of this and ask them what contaminate means? Put this word on the word wall. Ask the students what a control circle is. Tell them it is to compare and contrast their unknowns. Tell the students we are going to add water to each of the five substances and use the tooth pick to blend the each substance one at a time with the water. Tell them to make sure to use a different tooth pick for every substance. Each group can have a different test liquid or make this lesson longer by each group testing all the liquids.)

• Data:
• Water
  

  Unknown	Color	Shape	Texture	Odor	Other
  Red	Clear	Liquid	Gritty		Looks like face wash
  Blue	Opaque	Clumps	Clumpy
  Yellow	White	Liquid	Sticky		Glue
  Green	White	Clumpy	Sticky		Tooth paste
  Orange	Ivory	Solid	Hard

• Vinegar

Unknown	Color	Shape	Texture	Odor	Other
Red	Clear	Liquid	Gritty		Looks like sugar
Blue	White	Clumps	Clumpy
Yellow	White	Thick	Smooth
Green	Tan	Separated	Smooth
Orange	White	Clumpy	Hard

• Claims and Evidence:What we know about our unknowns: 1.we can find out about the properties (color, shape, texture, and odor.) 2. We can test with chemical liquids to find out about our unknowns. 

• Conclusion: How did our unknowns change once we added the different liquids to the chemicals? 

• Reflection: What questions do you have about this investigation? What worked and what did not work?