Scientific Method and Density

Laura Smith

Subject: Science

Grade Level: 4th-6th

Objectives:

Students will be able to list the seven steps of the scientific method and apply these steps in the lava lamp experiment.

Students will be able to describe in their own words their observations and results of the lava lamp experiment.

Materials:

·  Pencil

·  Plain white paper

·  White board

·  Clear, not colored, water bottles (one per student) filled ¾ with cheap vegetable oil

·  Alka-Seltzer tablets (one per student)

·  Tap water

·  Food coloring

·  Two small funnels

·  Copies of the lava lamp experiment (one per student)

Procedures:

  1. Get students attention and motivate them by asking if anyone has a lava lamp or has ever seen one. Ask a student to describe it and then inform the students they will be making their own lava lamp.
  2. Ask students to recall our previous day’s lesson on the steps of the scientific method. Write the first letter of the key word in each step on the board. Have students write the same on their paper leaving space to write what each letter means. (O, Q, H, P, E, A, D)
  3. Play scientific method song to help them remember the letters.
  4. Ask students about the first step: Observing. Ask them what the two liquids are in front of them. The second step is forming a question or what we want to know about these two liquids. We want to know what happens when we mix water with oil.
  5. The third step is forming a hypothesis. Ask students to give a definition of hypothesis and reemphasize that it is simply a guess of what they think will happen. Will they mix or not? If not, what liquid will be at the top and which at the bottom? Have students write their own hypothesis.
  6. Fourth step is a plan. How to do the experiment. That step has been done for them. Hand out copies of lava lamp experiment.
  7. Fifth step is to start the experiment and write down their observations.
  8. Pass out water bottles with oil. As the teacher I will walk around and pour the water into their bottles. Once the water is poured ask students to leave their bottle alone so the two liquids may settle. Discuss what happen and explain that the density of water is greater than the density of oil that is why it sank to the bottom. Have them write down what they observed. Next pass around food coloring and have each student put ten drops of food coloring in their bottle. Emphasis they are to put the cap back on their bottle when they are finished. Tell students to be careful with the food coloring and try not to get it everywhere. Reemphasize they are to leave their bottle alone, do not be picking it up or playing with it. Discuss what happens with the food coloring and have students write their observations down. Finally, pass out the Alka-Seltzer tablets, one per students. Ask student to break the tablet into about four parts. Have them place one piece at a time in the bottle. Discuss and have them record their observations.
  9. Sixth step is to analyze their results. Discuss the results and have students compare the actual results to their hypothesis.
  10. Seventh step is for the students to decide whether they want to keep their hypothesis or discard it.