Beacon Lesson Plan Library

EggCELLent Diffusion

Sherri Barber
Santa Rosa District Schools

Description

Students observe the effects of diffusion on eggs by observing the change in the egg's size and the amount of liquid substance that remains.

Objectives

The student understands the process of osmosis and diffusion.

Materials

-Raw eggs (3)
-Clear plastic cups (3)
-Vinegar
-Oil
-Water
-Measure tape (cm)
-Permanent marker or marking pen for beaker
-Rubber bands (3)
-Plastic wrap
-Graduated cylinder
-Lab sheet (see associated file)
-Science textbook
-Perfume

Preparations

1. Gather materials for lab.
2. Make copies of Lab Sheet (see Associated File)
3. Write questions on the chalkboard for students to answer as they read about diffusion.

Procedures

1. Put students in their cooperative groups. Have students review the following questions and answer them as they read about diffusion and osmosis in their science textbook:
A. What is diffusion? A: movement of materials from an area where they are more crowded to an area where they are less crowded
B. What is osmosis? A: movement of water through a membrane
C. What part of the cell controls the passage of materials in and out of the cell? A: cell membrane
D. What materials would most likely enter a cell? A: food, water, oxygen
E. What materials would most likely leave a cell? A: waste, carbon dioxide
F. What role does water have in diffusion? A: many substances dissolve in water before they move through a cell
G. Why is it not possible for some materials to pass through a membrane? A: the molecules of a substance may be too large to pass through a cell's membrane

2. Diffusion demonstration: Have several students stand in different places around the classroom. Have one student stand in a location and pump several sprays of perfume into the air. Have the other students acknowledge when they smell the scent by raising their hand. Students should be able to see how the scent moves from students that are close to the source to the areas further away as the scent diffuses in the classroom space. We can observe diffusion through the sense of smell everyday. Have students think of other examples of diffusion that they have observed through their sense of smell. Examples might include: waking to the smell of bacon frying in the kitchen on the other side of the house; entering the school building and smelling popcorn that was made down the hallway; the smell of smoke from a burning house that is miles away.

3. Review the answers to the questions. Point out the role of water in taking medicines such as aspirin. The directions of many medicines state that one should drink plenty of water when taking the medication. Why is that necessary? In order for the aspirin to take affect, it must dissolve in water so that the body can absorb the medicine.

4. Review the Lab Sheet (see associated file) with the students before breaking students into their cooperative groups.

2 Days later:
1. Students observe the results of the experiment and record them on their Lab Sheet (see associated file).

2. Students discuss their observations and conclusions with the class.

Assessments

Standard Assessment: Teacher will assess students using the Lab Sheet (see Associated File) and by checking their answers to the questions that were completed after reading about diffusion.

Process Standard Assessment: Teacher will observe students as they setup and do the experiment. The teacher will also check their Lab sheet to make sure that it has been accurately completed.

Extensions

Have students bring in an additional liquid to use in their experiment.

Attached Files

A two page Lab Sheet .     File Extension: pdf

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