Lava Lamp Lesson Plan


Objectives:

  • Students will be able to find the density of a liquid through the algebraic formula.

  • Students will be able to hypothesize what will happen to mixture after the three ingredients are added.

Context:

  • Concepts:

    • measurement

    • density

    • states of matter



  • Generalizations:

    • Every liquid has a density.

    • One can find the density of an object by dividing the mass of the liquid by the volume of the liquid.

    • States of matter come in many different forms.



  • Terminology:

    • density: the quantity of something per unit volume, unit area, or unit length

  • Liquid: has no fixed shape, but instead has a characteristic readiness to flow and therefore takes on the shape of any container.

    • Hypothesis: something not proved but assumed to be true for purposes of argument or further study or investigation

  • Essential Questions:

    • Why are is it important to learn how to find the density of a liquid?

    • How do you find the density of a liquid?


Procedures:
  • Introduction:

    • First I will tell the students that this lesson is going to be lots of fun. They are going to watch a fun reaction, and make their own lava lamps at the conclusion of the lesson. Students will receive a handout on the properties of matter and density. They will learn to identify each state and how it is connected to the experiment they are about to perform. I will then hand them two different liquids, I will have them find the density of the two liquids. They will find the density and figure out what each liquid is. They will be handed a 100 ml graduated cylinder, a triple beam balance, calculator, and vegetable oil and water. First they will weigh the cylinder, after they write down the weight they will pour the first unknown liquid (water) into the graduated cylinder to the 50 ml level. They will then weigh the cylinder with the liquid, and subtract the first weight from the second to get the weight of the liquid. The students will then divide the weight of the liquid by the volume of the liquid (50 ml) and that is the density (d=m/v). The students will do the same for the vegetable oil. They will then look at the list of common liquids and their densities to find out which liquids they will be using for the assignment. At this point an explanation of the experiment at hand will be given. Students will then be instructed to form a hypothesis, based on what they think will happen when the three ingredients are mixed. In regards to the students forming their own hypothesis, the students will be given guiding questions. For example: "What do you think will happen when the water and oil are combined? What will happen when the alka-seltzer is added? The purpose of the students forming a hypothesis, is to see if students understand what happens when different types of matter are combined. Students will also have to explain their reasoning behind their hypothesis. They will write their hypothesis down on a handout that will be given to them during class.

  • Body:

    • I will then demonstrate the experiment using a 2 Liter plastic soda bottle for the students while they they do their experiment in their own 473 ml plastic bottle.

    • First the we will fill the soda bottle 3/4 full with vegetable oil. Add water to the remainder of the bottle, which will be almost to the top but be careful not to overflow. After this I will have the children add 10 drops of the food coloring of their choice. The children will take their 8 pieces of alka-seltzer and drop one piece of a time into their soda bottle, oil water mixture. The mixture will start to bubble. We will wait until the bubbling stops and add another piece. Continue this added process until there is no more alka-seltzer left. Finally the students will screw on the cap of the bottle and rock the bottle back and forth and watch the wave of lava appear. For an added effect the children will place a flashlight under the bottom of the bottle. This will illuminate the bubbles for a fun effect for the students. As each ingredient was added to the water bottle, students will have been recording their observations in written form. For example, what occurs when the water is added to the oil? What happens when the food coloring is added? What happens when the alka-seltzer is added? Students will record what they see. By recording this information, students will be able to look at their data and see if their hypothesis was supported or rejected.

  • Conclusion: A discussion will take place as to what the states of matter were in our experiment. The solid was the alka-seltzer, the liquids were the vegetable oil, food coloring, and the water, and the gas was the carbon dioxide which was produced by the alka-seltzer.


Assessment:


  • I will assess their knowledge of the lesson on whether they know which liquid is which by grading their density worksheet in which they find out what the densities are of each liquid.

  • I will also assess the students on their formation of their predictions by grading their hypothesis worksheet on their content of the worksheet and the grammar and spelling on their worksheets.



Materials:

  • Hypothesis worksheet

  • Density worksheet

  • 50 ml cylinder

  • water

  • vegetable oil

  • alka-seltzer

  • water coloring

  • 1 two liter clear soda bottle

  • one 473 ml water bottle for each student

  • flashlights

  • triple beam balance

  • calculator