Unit/Lesson Topic: Earth Science/Permeability
Science Analysis – Definitions of Permeable Liquids
- being able to pass through solid substances. (written definition)
- Something is said to be permeable if liquids can pass through it (restated during closure for clarification).
- Permeability is the ability of liquids to pass through solid substances (another way of stating definition).
The purpose of this lesson is to familiarize students with a new concept. Students need to know what permeable means and they need to be able to recognize the difference between substances that are permeable with those that are not because understanding this concept serves as a basis for many decisions people make in the real world. For example, if you are having a picnic and you serve watery foods such as watermelon or baked beans on a non-coated paper plate, you could have a disaster on your hands or should I say lap! The water from the food will most likely leak through the plate. Another example is understanding that a rain jacket would be a wiser choice than a cotton jacket on a rainy day because the rain jacket is not permeable. Finally, a third and very important example is knowing to wear latex gloves (because they are not permeable) when doing first aid on another person because latex gloves serve as a barrier to bodily fluids (which are liquids).
“Examples” and “Non-Examples” labels
Chart headed “Characteristics of Examples”
Prewritten definition of permeable
Hands-on examples: paper towel, paper bag, cardboard, tea bag, paper plate, coffee filter, sponge, dirt, pine cone, net, strainer, wash cloth, cap, purse, Nerf ball, paper, cloth place mat, screen, cloth gloves, slotted spoon)
Hands-on non-examples: wax paper, plastic bag, Tupperware container, Ziploc bag, waxed paper plate, foil, seashell, rock, acorn, bucket, pot, tile, rain hood, plastic wallet, marble, sheet protector, plastic place mat, glass, latex gloves, non-slotted spoon
After a concept attainment lesson on permeability, the student will be able to:
1. Identify the defining characteristic of the concept permeable.
2. distinguish between substances that are permeable and those that are not.
Motivation/Introduction of Process
“Today we are not going to do things the normal way. You know how I usually stand in front of the class, tell you the concept, give you examples, and then we discuss the concept? Well, today I am not going to do that. Today, you are going to discover the concept instead of me telling you the concept. You will be in charge of figuring out what the concept is by investigating some examples and non-examples of the concept. This is how it will work. I am going to place some examples and non-examples of the concept on the table in front of you. You will study these objects and try to figure out the concept. You need to pay special attention to the examples because they represent the concept. Try to think about what characteristics the examples portray. When you have ideas, I will write them on this chart. If you find that a written characteristic does not fit all the examples showing, let me know and I will scratch it off the list. I will keep showing you examples and no-examples of the concept until you figure out the concept. Are there any questions? You may discuss this with your classmates, but don’t be afraid to just blurt out any ideas you have because you may have the correct answer. Once you have guessed the concept, as a class, we will construct a definition for the concept and label it.”
“Here are two examples.” Place the paper towel and paper bag on the table in front of the class by the “examples” label. “Here are two non-examples.” Place the waxed paper and the plastic bag by the non-examples label on the table. Remember to focus on the examples. Think about the characteristics or attributes that the examples share. If you have ideas, say them and I will write them on the chart. Possible student responses might include “paper items” or “recyclable”.
“Here are two more examples.” Place the cardboard box and paper on the table. “Here are two more non-examples.” Place the Tupperware container and sheet protector on the table. “Are there any more ideas? Focus on the examples.” Possible student responses might include “things that are sturdy” and “items made from trees”.
Cyclical Process: Continue to show two examples and two non-examples asking students to identify characteristics that the examples have in common until the students have identified the critical characteristic of permeable (liquids can flow through the examples). During this time, I would say things such as: “Pay close attention to the examples. What do the examples have in common? How are the examples alike? The non-examples are contrasting to the examples. They do not share the characteristic of the concept. Use the non-examples to help you identify the characteristic that the examples share. What do you notice about the examples? Tell me what you are thinking.” Continue writing characteristics that the examples share and crossing off characteristics that the examples no longer share. The remaining items are listed under materials.
Note: If students are having difficulty identifying the critical characteristic of the concept, you may allow students to break up into smaller groups to discuss the characteristics in further detail. Then have the students come back to the whole group and share what was discussed in their small groups. Groups may be able to do some problem solving and deduce the critical characteristic.
Once the students have identified the critical characteristic (that the items are items that liquid can flow through), have students formulate a definition. “Okay, now that we know the examples are things that water can flow through, let’s construct a definition for our concept.” Write the final decision of the students’ definition. “Does anyone know the formal name for the concept we just defined?” Allow students to respond. If students do not know, tell them the label. “The concept we just defined is permeable. What is the critical characteristic of permeable?” Allow students to respond. Then, show students the prewritten definition and read/explain. “Permeability is when liquids can pass through solid substances. Something is said to be permeable if liquids can pass through it.”
“You all did a super job figuring out the concept! Was it more fun learning something new this way? Now i am going to see if you really understand the new concept. What is the concept? What is it’s critical characteristic? I am going to hold up either an an example or a non-example. I want you to tell me whether the object represents an example or non-example of permeability. Does everyone understand? I also want you to explain why it is an example or non-example. Okay, here we go.” Ask each student to classify at least one of the items.
“Today we learned a new concept. You identified the concept by looking at examples and non-examples. You were able to identify a critical characteristic of the concept and define the concept instead of me telling you the concept and it’s definition. How do you feel about this process? Let’s review what we learned. What is the new concept? What is it’s critical characteristic? Can you give me a definition of permeability? Give me an example. Another example. Give me a non-example. Why is this item not permeable? Super! For your homework tonight, I would like you to write the name of the concept and definition of the concept. Then I would like you to look around your home and identify at least two examples and two non-examples for the concept. Are there any questions?”
The objectives will be assessed by observation of student responses throughout the lesson and during testing items (a checklist will be used to make sure all students respond, checking for accuracy) and homework will be collected, checking for accuracy of the definition and examples.