Activity 1a

Materials

Pencils, tape, tissue paper, scissors, string, hole punch

Procedure

Gear-up

1. Read the opening quote from Jonas Ramoth: If you open the door of a warm house on a cold day, there's the wind. Ask them what they think Jonas means by this. Ask them to imagine this situation and to diagram and describe in their journals the movement of air when the door is opened. Students will have had lots of experience with this phenomena and will probably say things like –hot air rises” and –cold rushes in”, but use questions like the following to probe their understand-ing of air movement particularly with regard to the convection cycle.

• Can you feel air movement or just a temperature change?
• Does air move into or out of the house or both?
• If cold air is moving into the house, what is happening to the warm air ?
• If the air is moving, are hot and cold air moving in the same way at the same place?

  Discuss these ideas as a class, recording predictions and explanations. (EA: prior knowledge of convection)

2. Provide students with a copy of the Learning Cycle Model Scoring Guide** and let them know that their learning will be assessed using this checklist. Students will use the form as a self-evaluation and you will use it as a checklist as students work through the explorations and as you review their journal entries.

3. Have students construct wind detectors by using string to attach a 1 x 3 inch strip of tissue paper to a pencil as shown. (You'll want to test design ahead of time to make sure it is weighted sufficiently to swing with wind.)
4. Ask them to go to an outside door on a cold winter day***, open the door just a few inches (from inside) and hold the detector near the floor. Observe and record which way the tissue/wind moves.
5. Now hold the detector in the middle of the door and then near the top. Observe and record movement of wind detector.
6. Ask which way the air is moving at each of these locations. Does the air movement seem to be as strong at each level? What are your ideas about this? How do these observations compare with your original ideas?
7. How do you think air would move if you opened the door of a hot oven in a warm room? Test and find out.
8. Discuss how these observations compare with their original ideas. Have them revise journal diagrams if they want.

• Initiates activities with no forethought or avoids activity completely
• ignores needs and contributions of peers

• interacts with phenomena as instructed
• works politely with peers, but sticks to personal agenda

• asks clarifying questions
• uses a variety of methods to interact with the subject
• works cooperatively with peers and gains insights from their activities

• no organized attention or skills applied to task at hand

• measurements, observations, and classifications are recorded, but with little attention to detail

• makes careful observations, measurements, and classifications
• records measurements, observations, and inferences

• shows minimal intellectual interaction with materials being manipulated

• fluid interactions with phenomena, but they sometimes are off target with intended activities

• identifies and seeks to expand personal understanding of the concept or phenomena

• shows little participation in discussions
• demonstrates non-supportive behavior for others' input

• engaged in discussion as a participant
• does not initiate many questions

• asks thoughtful questions
• shows respect for other ideas

• does not distinguish between observations and inferences
• looks upon guesses as fact

• has basic understanding of the differences between observation and inference.
• understands that a hypothesis is a kind of scientific guess

• distinguishes between observations and inferences
• identifies relevant observations and interpretations
• looks upon guesses as hypotheses to be tested

• jumps to conclusions that are not based upon recent manipulations of the phenomena

• considers data before making conclusions

• avoids jumping to conclusions
• identifies alternative explanations for phenomena

• does not recognize applicability of knowledge gained from both successes and failures of experimental process

• creative application ideas, but they do not address personal or societal needs

• offers to apply new knowl-edge to positive benefit of society

• does not refer to principles and concepts discovered in earlier generalizations

• applications loosely associated with principles of concept

• refers to principles which were discovered in the generalize stage in spite of new context

• does not offer applications of new knowledge regardless of context

• applications offered, but does not transcend original context

• transfers application of concept to new context

Activity 1b

Materials

Per group: large, wide-mouthed jar, water, baby food jar, aluminum foil, food coloring, rubber bands, string, sharp pencil

9. Have students fill a large (gallon), wide-mouthed jar two-thirds full with cold water. Next, put three drops of food coloring in a baby-food jar. Fill the baby-food jar to the top with hot water. Cover it with aluminum foil and secure the foil tightly with rubber bands. Tie a string around the baby-food jar and lower it into the bottom of the large jar. Predict what you think will happen when you punch a hole in the foil and record prediction in journal.
10. Wait until the water is still and then punch one hole in the foil with a long pencil. Watch and record what happens. (Nothing happens because the cold water is heavier than the warm water and pressing down upon the hot water, but there is no –escape hole” allowing the warm water to be pushed out by cold.)
11. Ask students why nothing happens with just one hole. Ask for solutions and then have them punch a second hole, observe and record.
12. Ask what they observed when the second hole was punched? Did the colored fluid rise from only one, or both of the holes? What are your ideas about this? How long will it keep rising? After a long time, what will the fluid in the large jar be like? What are your ideas about why this is so? (The colored hot water will rise from one hole in a fairly straight line. As it rises, it will cool and begin to both sink and diffuse into the cold water as water temperatures equilibrate. Depending upon water tempera-tures, a complete convection cell may or may not be visible with the red/hot water.)
13. Ask students to compare this activity to the door activities. What do they now think the air movement in a warm room on a cold day might look like?

Activity 1c****

Getting Ready

The last two activities demonstrated what happens when fluids of unequal temperature meet. This activity demonstrates how warm and cold surfaces affect air. To do this, an observation box and smoke-filled air piston must be created as follows:

Observation Box: 1 per Student Team

1 cardboard box (about 30 cm x 30 cm x 50cm) per team
clear plastic food wrap
plastic tape
straws
Smoke Piston
1 large air piston
1 plastic straw
heavy cotton string, 12 cm long
matches
scissors
baby food jar of tap water

1. Remove one side of the box; then cut a window in two sides as shown. but leave about 1/3 of the top intact. Tape plastic food wrap over the windows so that they are airtight. In one end of the box, cut a small hole just large enough to insert a plastic straw.
2. Cut the straw into 4-5cm lengths. Cut the string into lengths of about 4cm. Double one of the pieces of string twice or more until it will fit snugly in the end of a piece of the plastic straw. Leave about 1/2 cm of the doubled string sticking out of the straw. Repeat the procedure for the other pieces.
3. Slip a section of the prepared straw onto the air piston. Light the string, being careful not to melt the straw. Collect smoke in the cylinder by slowly drawing out the plunger. Remove the straw and lay it aside where it won't burn anything. You may need more smoke later. Insert figure six with step 3 narrative.

4. Working in student teams, place a pan of cold water, ice water, ice cubes or snow inside the observation box. Be sure the straw is in place through the end of the box. The end of the straw should not be over the pan of water.
5. Insert a smoke-filled air piston into the straw of the observation box. Gently force smoke through the straw into the box so that it moves very slowly over the cold water. Observe and record what happens to the smoke.
6. Repeat using a pan of hot water. Observe and record what happens.

7. Ask student to report what they observed with the smoke and cold water. (See diagrams below.) Ask them to use arrows to diagram the movement of air in the box. What are their ideas about this? How about for hot water?
8. Ask how these observations and ideas compare with their earlier ideas about the open door.

9. Ask students what their ideas now are about air movement when a door is opened on a cold day? Ask them to review their original journal predictions and revise the diagram/explanation using evidence from explorations as support for their ideas.
10. Take students outside on a calm day when smoke is visible from smoke stacks. Ask them to diagram and explain smoke movement and air temperatures at different levels using evidence from these explorations in support of their ideas. (See sample diagram)

11. Ask students to imagine a hot summer day in Selawik where the air temperature is much warmer than the water temperature of Selawik Lake. Ask them to diagram air movement and explain it using evidence from these explorations.
12. Ask what might wind patterns be like in the late fall just before freeze-up of Selawik Lake when the water temperatures are warmer than air temperatures, particularly at night? Do your predictions match your experience? Check with the TF to see if your predictions match his or her experience.