Magnets Compel Understanding of Science

Transcription

1 Magnets Compel Understanding of Science Objectives Students will be able to name 2 properties of magnets Students will be able to discuss the strength of magnetic attraction Students will be able to define magnetic poles and fields Students will know a compass always points north Students will successfully complete four stations experimenting with the properties of magnets and what they can do Students will actively participate in a closing discussion of Magnets and Science Suggested Grade Level Pre-K through Second Subject Area(s) Science Timeline Unit Five 50-minute class periods Background Teacher- Objective is to understand the fundamentals of magnetism and enable the students to demonstrate the process of science by posing questions and investigation phenomena through language, methods and instruments of science. The teacher will need to invest a good deal of time in preparation by gathering small items and setting up stations. Day 1- Set up two stations. Each station has a bag of items and prediction sheet. Day 2- Set up four piles of items magnetic and non-magnetic. Day 3- Set up compass, needle, string, and bar magnet per group. Day 4- Set up 4 centers- Mystery Sand, Magnet Maze, Magic Trick, and Make a Statue Student- An introductory knowledge of scientific inquiry is needed Materials Magnets of various shapes, sizes, and strengths Paper clips Nails Observation guide Iron filings Paper Pencils Clay

2 Glass jar Wood Spoon Keys Comb Marble Building blocks Aluminum foil Cork Cardboard Coins Plastic bag Battery Compasses Tissue Balloon Bolt buttons Ruler Scissors Washers Staples Bolts Black electrical tape Bar magnet String Lesson-Day 1 Properties of Magnets 1. Vocabulary Magnet- polarized object that attracts metal Natural- found in nature Man-made- not found in nature but created by humans or technology Magnetite- mineral that is a natural magnet Steel- metal used to make man-made magnets; also can be picked up by Iron- a metal which magnets can attract or pick up Poles- the ends of magnets Field- the space around the magnet Attract- draw toward, pull 2. Magnets come in many sizes, shapes, and strengths. Compare the strengths of various magnets by determining how many paper clips can be held in a chain by each type of magnet. 3. Place assortments of magnets at different locations in the classroom. 4. Have students go in groups of 3 to each station and rotate at intervals when instructed to do so. 5. Each magnet has a north pole and a south pole. A magnet is strongest at its pole. Sometimes the letters N and S are stamped into the magnets to

3 label the poles. Look at the various magnets and find the North and South Pole of some of them. 6. The space around a magnet is called the magnetic field. (Have a demonstration using two children standing far apart. One child holds a magnet; the other holds a paper clip.) Why isn t the paper clip sticking to the magnet? (Are they too far apart)? Have them move slowly closer together until the paper clip is attracted to the magnet. The paper clip must be within the Magnetic Field to stick to the magnet. 7. Divide students into groups of 3 so they can combine their magnets for greater exploration. Use the clay for bases for the pencils to keep them sturdy and upright. Ask the question, What would happen if you put two ring magnets on an upright pencil? Have students predict on what will happen and discuss their predictions. 8. Now provide time for students to try different ways of stacking two magnets on each pencil. Have the students make predictions to find out how close they were. Allow students to use all their magnets to fill up their pencils with floating magnets and record what they see. Let them continue exploring by arranging different numbers of magnets in various ways on their pencils. 9. What do magnets attract? Divide the class into 2 groups. Each group will begin at a station. Each station has a bag of items and prediction sheet. Someone should write do the findings and someone should be the tester (has 1 magnet). 10. At each station Empty bag Predict if each item will be pulled to or pushed away from the magnet and should be written done on the worksheet provided. Test the predictions with the magnets Make 2 piles items that a magnet will attract and items that will not according to the group Mark each item as attract or not attract 11. Repeat until all stations have been visited Lesson- Day 2 Strength of Magnets 1. Have 4 piles of items. 2. Ask students if they have a refrigerator. Ask them if they hang anything on their refrigerators? How? Anyone use magnets? Why does the magnet still work even when the paper s in the way? Magnetism can sometimes go THROUGH objects to attract the metal! 3. Have a large paper or board at front to mirror the student worksheets. 4. Hand out observation worksheet to children. Have them take out a pencil. Ask them to make predictions if they think that magnetism will go through each of the items. List them on the worksheet if possible. 5. Read them one at a time, showing students the item, as it is read, and ask them to draw a smiley face for yes and frowning face for no in the blank.

4 6. Allow for them to choose an object in the room and test it out. Let them know that their answer is a prediction, or a guess. It is what scientists do before they know an answer to something. It is by testing our predictions that we find out answers to many questions. 7. Break the children into groups of Have each of them fill out the observation part of the worksheet by testing each one of the materials or have parent volunteer s assist. 9. Explain that several items (wood, plastic, cardboard, and glass) will be at particular locations (show them) and that they must share. If someone else is using it, then they must wait in line or do another object first and then get in line again. 10. When done, ask them to get a new bag with several items in it. Ask them to use these materials and see what they do when you try to attract these through the same objects. 11. Allow minutes for exploration or adjust as needed. 12. Have the children meet back in their sets where the teacher has prepared a large piece of paper that looks like their paper (the chart). 13. Ask for results and have students write a smiley face or frown face, depending on if the magnet would attract through the object. 14. Ask the children how strong magnets are? Do magnets have different strengths? If so, what makes one magnet stronger than another? 15. Break into 2 groups. 16. Supply each group with a handful of bolts, 1 donut magnet, 1 square magnet, and 1 round magnet. 17. Ask the children to test the strength of the magnets by picking up as many bolts with one magnet and writing that number down. Then do the same for the other magnets. You may substitute paper clips for bolts depending upon magnet size and strength. 18. When they have finished, they may then come up and get the following: paperclips, piece of string, and small amount of iron fillings. They will be asked to find other ways to test the strength of magnets; they may use the materials at their desk. Allow for up to 20 minutes of exploration. More if they look occupied and there is time to spare. Lesson- Day 3 Compass Activity 1. Now let s pretend you have been camping and now you are lost in the forest. How would you find your way out? Do you know how you could use a magnet to find your direction? Does anyone know what this is? (Compass) Do you know what it does? Do you know how it works? (Needle is a magnet attracted to magnetic north pole) What would this mean for a person who is lost in the woods? (N points north, could us to find out what direction you needed to go). So remember we are lost in the forest. 2. Groups are given a needle and magnet. Compass maker strokes the needle 50 times with the magnet.

5 3. Magnet is returned and the needle is tested with the hanging bar magnet. N is labeled by placing black tape on one end of the needle. Groups will determine N, S, E and W (each starting in a different direction) and will list 1 item for each group member that is in the classroom at that direction. 4. Groups rotate until all four directions have been covered; end up in original direction they began with. 5. Group will draw a map or write directions using the landmarks they have recorded to find their way from one point in the room to another, must use at least 4 landmarks that are in all 4 directions. Lesson- Day 4 Attract or Repel Materials Doughnut shaped magnets Pencils Sand Iron filings Maze made by teacher or parent volunteer String Magnet wand Paper clips Bolt Piece of tag board Tape Cookie sheet 10 magnetic buttons and any other magnetic and non-magnetic supplies that you wish 1. Group the children into 4 s. 2. Provide each group of children with one pencil and 4 doughnut shaped magnets. 3. Ask the children to place the magnets on the pencil and 4 doughnut shaped magnets touching each other, they are not touching the magnets and nothing else is touching the magnets (besides the pencil). Ask them to raise their hands when their group has finished. When a group has finished, ask that group some questions. 4. Remember that sometimes magnets attract, or come together and sometimes they repel, or push apart. What are your magnets doing now? What are they doing when you place them onto another magnetic metal? Please make your magnets attract to each other. Please make your magnets repel from each other. Remember that every magnet has two parts, a north pole and a south pole. Lets say that the blue side is the north and the south part is red (draw on board). What happens when we

6 put the north and south side together? Let them try to do this at their desks. North against north, south against south. 5. Center One: The Mystery Sand -In front of the class (before separating for centers), mix up some iron filings with sand and place it in two separate containers (one for each group). Let them know that they will have to figure out a way to get only the iron fillings out and onto the bowl next to it. Show them all the materials they may use to help them. Those materials are tweezers, magnifying glass, and magnet wand. Also at this station will be the two containers with the mixed sand/iron fillings, two bowls, and a working surface. Let them know that they should let you know when they finish. But before they leave, it is their responsibility to mix it back up for the next group. 6. Center Two: Magnet Maze Teacher should either show the children the maze that was pre-made or show the children how to make a simple maze. Next, ask the children to find a way make one magnet go all the way through the maze. They may use any off the following tools to help them: A string, magnet wand, paper clip, doughnut shaped ring, and/or a bolt. One last rule, they are not allowed to let any of these objects touch the magnet that is to travel through the maze. 7. Center 3: Magnet Magic Trick Students are to use the tools provided to create some kind of magnet magic trick. The following tools should be provided: magnet wand, 2 doughnuts shaped magnets, pieces of string, paper clips, bolts, some iron fillings, piece of tag board, tape, bolts, and any other item you wish to add. Let the children demonstrate their magic trick to the class before every group switches. 8. Center 4: Make Statue Allow the students to manipulate iron fillings along with other magnets and misc. items to create a figure. Supply a cookie sheet, several doughnut shaped magnets, container of iron fillings, 10 magnetic buttons, and any other magnetic and non-magnetic supplies that you wish. Do not attach the magnets for them. Let them discover that they need the magnets on the bottom of the sheet if they are not going to use any other magnets in their figure. Let the children share their finished product with the class before each group switches. Lesson- Day 5 That s a Wrap! 1. Does everyone remember when we compared the strength of the different magnets by seeing how many paper clips it would pick up? Did you think that magnets have different strengths? What made you think this? What do you think makes one magnet stronger than another? 2. When you were testing the items in the centers to see if they would attract or not, why do you think that items that the magnet attracted were affected (and why where the non-magnet items not). What properties are similar

7 among the attracted items? What could a magnet be used for in everyday life? 3. When you hold a magnetic item close to a magnet why does it attract and not attract if you hold it far away 4. Will a magnet attract any metal object? Why or why not? Could the earth be considered a magnet? How could you consider it so? If you dropped a magnet into a pail of water that contained iron fillings, would the magnet attract the fillings? Why or why not? 5. Name 2 uses of magnets in your home or school. 6. Name 2 things a magnet will not attract. 7. Opposite poles attract and like poles repel. How do we know that this is true? Describe an experiment that our class has done to prove that this is true? 8. If you are lost somewhere how could a magnet help? 9. Why does the north pole of one magnet repel the north pole of another magnet? 10. Why do you think that at the mystery sand station that the iron fillings attracted to the magnet and the sand feel back into the box? 11. How did you get the ball through the maze? 12. What else did you learn? (Science is compelling! ) Extensions Find a science museum with a hands-on magnet activity. Go to the internet and do further research and experimenting. Home projects? Lesson 6 Extension- Invention Materials Needed 1 three-foot long wire 1 nail 2 batteries in holders 1 breadboard paper clips push pins Procedure 1. Wrap the wire tightly around the whole length of the nail. Wrap all of the wire but about 6 inches at each end. 2. Try to pick up the paper clips by touching them with the nail. What happens? 3. Hook up the batteries so that electricity is running through the wire. 4. Try again to pick up the paper clips. What happens? Why? Evaluation/ Assessment Students were able to name 2 properties of magnets Students were able to discuss the strength of magnetic attraction Students were able to define magnetic poles and fields Students can express that a compass always points north

8 Students successfully completed four stations experimenting with the properties of magnets and what they can do Students actively participated in a closing discussion of Magnets and Science Resources