Introduction: (Initial Observation)
We all have magnets in different forms attached to our refrigerators. These magnets are often plastic, metal or ceramic. They may also be hidden behind a decorative figure. Why do we call them refrigerator magnet? Did you ever try to place these magnets on other surfaces?
What material are attracted by magnets? Can we use magnets to identify other material?
Find out about what you want to investigate. Read books, magazines or ask professionals who might know in order to learn about the effect or area of study. Keep track of where you got your information from.
What are magnets?
Magnets are objects that attract anything containing iron, cobalt or nickel. Magnets occur naturally but can also be made artificially, by stroking a piece of steel with another magnet, for example. Every magnets has two zones, called its north-seeking poles, where its attraction is strongest. Magnetized materials are made up of millions of atomic-sized magnets, called domains. The north-seeking poles of these domains all point the same way.
What is the real life application of this project?
Magnets have many industrial applications; however, they only work on materials that are attracted by magnets. For example in food factories, they use magnets to attract nails and small iron pieces that may have fallen into the food accidentally. Although magnets can be used to extract pieces of iron, they cannot be used to extract broken glasses that may have fallen in food products. This project will help you to identify the materials that are attracted by a magnet. In this way, you can use a magnet to handle, move, filter or extract such materials.
What do you want to find out? Write a statement that describes what you want to do. Use your observations and questions to write the statement.
The purpose of this project is to find out what material or objects will be attracted by magnet.
You may also write it like this:
The purpose of this project is to find out what household material or objects will be attracted by magnet.
When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other.
Independent variable (also known as manipulated variable) is the type of material that you test. Possible values are: Wood, nail, paper clips, coins, dollar bills, rocks and sands.
Dependent variable (also known as responding variable) is the attraction by magnet. Possible values are Yes and No.
Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis.
This is a sample hypothesis:
Only iron can be attracted by magnet.
This is another sample hypothesis:
All metals can be attracted by magnet.
Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a “control.” A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral “reference point” for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a “controlled experiment.”
What is attracted to magnets?
Take a strong magnet and go around the house to see what will stick to it or feel like it is attracted to it. Keep a list of the items you tried, and if the attraction was strong, weak, or none. Then try to figure out why.
Try especially different types of metals, for example:
|iron and steel||nails, screws and nuts|
|stainless steel||special hardware, some kitchen sinks, most everyday forks and spoons|
|brass||special screws, kick-plates on front doors|
|copper||old pennies, copper pipes|
|silver||expensive silverware, some jewelry|
|gold||wedding rings, grandma’s teeth|
|mercury||thermometer – no need to break the thermometer to do the test|
|nickel||some coins, US nickels are made of 75% copper!, try Canadian nickels|
|tungsten||filament in light bulb|
|magnesium||from a science supply store, used in a ribbon form for burning in air, or from a hardware store that carries magnesium floats for working with concrete|
|coins from several countries||try Canada, England, China, Japan, Germany|
About the US coins, I know the following:
Before 1982, the penny was 95% copper. After that, it was changed to 2.6% copper. It is mostly a zinc alloy with a copper coating.
The nickel is 75% copper.
The dime, quarter and half dollar is 91.67% copper.
The Susan B. Anthony dollar is 87.5% copper.
The new gold-colored dollar is 90% copper.
Below is a photo showing some of these metals, and a photo showing copper balls.
Besides seeing what effect a strong magnet has on different metals, try and find out the effect it has on different minerals. A great source of minerals is found in the shops of most public, natural and science museums and in science shops or nature stores at malls. They usually have a stand with several different types of colorful minerals displayed; often the pieces are highly polished. They come with a small card describing the mineral, and cost about $1 per item.
Blue lace agate
Bornite (Peacock ore)
Iceland Spar (interesting optical properties)
In particular, try minerals with iron or nickel in them. An interesting science fair project would be to have several types of minerals on display along with a wand magnet. You can see which minerals are strongly attracted to the magnet (can be picked up by the magnet), which are slightly attracted to the magnet, and which are not attracted at all. Try to predict what category each would fall into.
Here are some minerals that are strongly or slightly attracted to magnets:
(This is usually the very shiny, black, heavy mineral found in the displays, shown at the left in the first photo. Some jewelry is made of hematite.
(This may very likely be a weak magnet by itself! Remember, this was what started the whole study of magnetism to begin with in ancient Greece. This is seen in the fifth photo above.)
Don’t have access to minerals?
If you don’t have access to minerals for this experiment, move your magnet in the sands of a beach or your backyard. You will certainly find some small minerals that are attracted by your magnet.
Try other materials, too, like wood, plastic, carbon, cotton, wool, glass, concrete, leaves, CDs, and so on, which you can find around the house.
Some things which will be attracted to or stick to a very strong magnet, like a rare-earth magnet, is the tape from a VCR or audio tape, a dollar bill, and the surface of a floppy disk. The reason these items will stick to a magnet is because of the very small particles of iron used in the ink of the dollar bill, and the iron oxide (ferric oxide) used as the recording medium for the VCR and audio tapes and for the floppy disk. (Please only use a tape or disk which you want to destroy!)
Let’s try an experiment:
As you can see in the photo above, the tape from a VCR is attracted to the rare-earth magnet. The magnet will erase the information contained on that section of the VCR tape. I used a pencil to hold open the flip-top cover.
How about a dollar bill?
On the other two photos, you can see how the bill is attracted to the rare-earth magnet.
Take a crisp bill.
Fold it about 55% of the way along its length.
Lay it on a table as shown with the longer portion on the table, the shorter portion sticking up.
Bring the magnet close to the edge of the bill.
Watch the bill spring toward the magnet.
The reason for the attraction is that the ink on the bill has some iron particles in it.
Magnets can damage televisions and computer monitors
Warning: This experiment may cause permanent discoloration on a T.V. or computer monitor.
In this experiment you approach a small magnet to a TV screen or Computer Monitor to see how does it affect the image. Magnets can cause deformation and discoloration of the screen. If your magnet is strong or you repeat your experiment many times or your Television does not have protective features, this experiment can cause a permanent discoloration and deformation of images. To reduce the risk of a permanent discoloration, do not make the magnet close to the corners or edges of screen. Modern LCD screens are not affected by magnets.
Use magnet to identify different material
When objects are coated with paint, it is hard to find out what material they are made of. Some times we nock at them an listen to the sound. Sound can help us to guess the material. Magnet can be another help. Test some painted metals and guess if they are steel or not.
To see what effect a magnet has on floppy disks:
Take a floppy disk and try these things with it. Be sure to record exactly what you do and your observations – the two most important parts of an experiment!
Be sure to try some typical refrigerator magnets (usually very weak since they can barely hold one piece of paper to the fridge door) as well as some stronger rare-earth magnets (neodymium-iron-boron magnets which can easily hold a stack of 20 sheets to the fridge).
Also, vary how the magnet approaches the floppy disk and leaves the disk.
For example – directly toward it, perpendicular to the plane of the disk,
or across the face of the disk, in parallel to the plane of the disk.
Perhaps a quick approach and a slow approach could also be compared.
Try the top side and the bottom side of the disk.
Even try moving the magnet around in a circle on the face of the disk.
Maybe even have a floppy held to the fridge by a magnet for a week to see if time has any affect.
If you can make an AC electromagnet, that would also be a great addition for comparison.
What kind of data will you put on the disk in order to see if the data has been corrupted?
Perhaps some bitmap images would work well, with a simple pattern of black and white squares. They are usually large files so they would cover a large part of the disk. Also, looking at the image would be a very quick and easy way to determine if any bits were changed.
Another method would be to have a large data file on the disk, and do a file compare to the original which is kept on the hard drive.
Materials and Equipment:
For the experiments of this project you will at least need to have one magnet. Any inexpensive magnet can be used, however a long magnet such as wand magnet or bar magnet is preferred.
Results of Experiment (Observation):
Experiments are often done in series. A series of experiments can be done by changing one variable a different amount each time. A series of experiments is made up of separate experimental “runs.” During each run you make a measurement of how much the variable affected the system under study. For each run, a different amount of change in the variable is used. This produces a different amount of response in the system. You measure this response, or record data, in a table for this purpose. This is considered “raw data” since it has not been processed or interpreted yet. When raw data gets processed mathematically, for example, it becomes results.
After you test different objects with a magnet, record the results of your experiments in a table like this:
No calculation is required for this project
Summary of Results:
Summarize what happened. This can be in the form of a table of processed numerical data, or graphs. It could also be a written statement of what occurred during experiments.
It is from calculations using recorded data that tables and graphs are made. Studying tables and graphs, we can see trends that tell us how different variables cause our observations. Based on these trends, we can draw conclusions about the system under study. These conclusions help us confirm or deny our original hypothesis. Often, mathematical equations can be made from graphs. These equations allow us to predict how a change will affect the system without the need to do additional experiments. Advanced levels of experimental science rely heavily on graphical and mathematical analysis of data. At this level, science becomes even more interesting and powerful.
The results table will also serve as the summery of results.
Using the trends in your experimental data and your experimental observations, try to answer your original questions. Is your hypothesis correct? Now is the time to pull together what happened, and assess the experiments you did.
What did you find out? Do you now have a fairly extensive list of things magnets can and cannot attract?
Related Questions & Answers:
What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.
Problem with 2 or 3 unknown rods
Suppose you are given 2 metal rods: one is a magnet, the other is made of iron. However, both of them are painted so they appear to be the same. Their weight is the same. You are in a room with no windows so you can’t tell where North is located. You have no other objects with you. How will you be able to determine which rod is the magnet and which rod is iron?
Suppose you are given 3 metal rods: one is a magnet, one is made of iron, and one is made of brass. However, all of them are painted so they appear to be the same. Their weight is the same. You are in a room with no windows so you can’t tell where North is located. You have no other objects with you. How will you be able to determine which rod is the magnet, which rod is iron, and which rod is brass?
Check here for the answer.
If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.
If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.
Visit your local library and find books about magnet. Use such books as your references.