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Above all, you want to keep the science experiment/demonstration short and simple.
I teach college computer science classes, and I’m amazed at the number of students who don’t know that you can make a magnet by twisting a wire around a nail and hooking it to a battery. If time permits, you might ask what would make the magnet stronger. Some think that the size of the battery will determine the strength of the magnet (“D” vs. “AA” for example). You can also suggest more wraps of the wire around the nail. Which will pick up the most paper clips? This is very simple but informative.
Related: What materials are attracted to a magnet? Try aluminum foil, steel, stainless steel, a nickel, a dime, a penny…
You could couple that experiment with the flip-side: a magnet moving past a wire induces current to flow in the wire. Get a 12 to 15 volt DC motor (available at Radio Shack) and hook the terminals directly to an LED. Spin the motor with your fingers and the LED will light up (briefly). This demonstrates how the power company generates electricity for your home.
Someone mentioned surface tension. A good demonstration of this is to sprinkle talcum powder or black pepper on the surface of water in a pie pan. Rub your finger on some soap, and touch the water in the pan. The powder will scatter in all directions because the soap breaks the surface tension.
A variation on the vinegar/baking-soda demonstration is to mix the two in a container with tall sides (like a drinking glass). The carbon dioxide produced is heavier than air and will hang in the container. Light a match, and slowly pour the carbon dioxide from the container over the match. The match will go out because of lack of oxygen. The effect is neat; pouring an invisible gas out of the container over the match.
Have fun….and put your heart into it…
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Put a couple of teaspoons of baking soda in a glass. Hold a lit match or candle over it as you add vinegar. Combining the two will release carbon dioxide and put out the flame.
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You could always do the old slice of bacon in glass of coca cola - gross & fasinatin' at the same time - also could save you $$$ later in life when they refuse to drink pop! ;-)
*Wolvie, now tell me about that, please! It should be an "old" slice of bacon? Or does the coke "eat" the bacon?
*Your second choice, kai. It really does. And the scum left behind, blecch!I actually meant that as a joke ya know. Don't want to gross the little ones out!
*LOL just bringing them some "food" science :)
*A couple other ideas came to mind...I did these with my daughter's Brownie GS troop when they were either first or second graders:1) Mobius strips. They're easy to do and the kids were amazed trying to figure out how they "worked".2) We did several things with color. Mixing primary colors, etc, to get other colors. Basic color wheel stuff. One small experiment we did as an offshoot was taking a white coffee filter and drawing a heavy black magic marker (water soluble) line across it. then place the bottom 1/4" or so in a pan of water. As the filter absorbs the water, the water is drawn through the black marker line. As the water is "drawn" through the marker, it breaks out the various colors used to make the black ink. It causes a small rainbow-type effect to show up avove the black marker line.I had to experiment with a few markers to get one that worked well. We never got a pure ROYGBIV spectrum, but did get 4 or 5 of them. They liked both the mobius and color mixing quite a bit...but if forced to choose, they were more enchanted with the mobius strips. They liked the coffee filter trick as well, but they get a fair dose of "color wheel" mechanics in art class.Of the two I'd vote for mobius strips. Scissors, tape and paper are all you need, and not much of each at that. Low cost, big WOW, small mess.
*Jim O,I helped some kids with a science project at school a few years back. Our project was the surface tension of water.Some experiments I remember were: Bend an end of a paper clip up and set it on some water in a pan. It floats! Then put one drop of dishwashing liquid into the water as far away as possible from the paper clip and it instantly sinks (soap breaks the surface tension)We filled up some glasses as full as possible with water and asked the kids how many drops of water they thought could be added to the glasses before they spilled over. (10? 20?)Then would add sometimes hundreds of drops of water and watch the surface of the water rise above the glass, called a meniscus.jiml
*Jim L is onto something with this "surface tension" stuff. I remember an experiment I saw once. We got a glass of water, a small piece of tissue, and sewing needle. Lay the needle on the tissue, and lay the tissue on top of the water. (flat)Gently push down on the edge of the tissue until it sinks and leaves the needle floating on top of the water.
*Used to love watching Mr. Wizard when I was younger; the crushing can was a favorite of mine!A little science note...The marker experiment shouldn't necessarily create a rainbow-like spectrum, but it does spread out the different compounds that make up the ink.What's happening is the different compounds(chemicals) in the ink are different sizes and some are more attracted to the water or the filter paper. More polar compounds would likely move farther; the compounds with weaker polarity would probably move less.This experiment works on the same principle as electrophoresis of DNA.That separates DNA fragments cut by a particular enzyme by applying an electric potential across a gel. Kinda like when they proved OJ(or his evil twin) was guilty.But that could get a bit in depth for 7 year olds.Ben
*I'll follow up on Mongo's - but mix colored light - which is additive (rather than subtractive of paint and ink and so on). Red and green mix to orange, red, blue and gree mix to white. Easy to do with flashlights and color media ("gels") held on with rubber bands.
*My favorite is the "exploding can" trick:Put a trash can upside down on the table, fill it with natural gas by venting some under the can (slip the can near the edge of the table and sneak the hose up there).The gas will stay in the can because it is lighter than air.Now you prove that things only explode when the air / fuel mixture reaches the correct proportion and not before:Poke a small hole in the 'top' of the inverted trash can and light the little stream of gas escaping.It will burn with a nice, little flame for a while until the ratio of gas inside the can to air is just right and BOOM, the can will fly up in the air.Great for keeping their attention.Maybe not appropriate for 1st graders, though, now that I think about it.Nevermind.
*My brother used to take giant balloons and inflate them using his oxy-acetylene torch to about 2 feet in diameter. Tape a long piece of toilet paper to the side, place outside and light the "fuse". I was standing about 60 feet away when it went off and I could feel my hair move as the blast wave went by. You could hear the sound echo over the whole county... I still giggle when I think about it - 25 years later.Then we went in the house and watched the sheriffs cars cruise by.I heard a friend of his put one in an old Volkswagen.Well, maybe this "experiment" wouldn't be appropriate for first graders either.
*We had a Girl Scout meeting today, I asked the girls what their favorite experiments were in the first year or two (1st and 2nd grade). One they mentioned was similar to Jeff's.I took a 13" x 9" x 2" baking pan and filled it with about 1.5" of water, then added a few drops of food coloring. In the center of the pan we stood a candle, 3-4" tall.Light the candle, once you get a good flame, place an inverted wide-mouth mason jar or equivalent over the candle so the mouth or the jar is in the water. The flame will heat the air inside the jar, causing it to expand and bubbles will come out from under the lip of the jar. The flame will die due to oxygen deprivation. Once the flame is snuffed, the air inside the jar will cool, drawing colored water from the pan up into the jar.Once it stabilizes, I had the kids place ice cubes on top of the mason jar. It cooled the air in the jar and more water was drawn in. Remove the ice cubes and have them place their hands on the jar. Their body heat warmed the air in the jar, causing the air to again expand and the water level to decrease.This year (4th grade) they made their own "barometers". Wide-mouth jars with sections of balloon stretched tightly over the mouth, secured with rubber bands. Glue a straw to the balloon, tacked with one end centered in the jar's balloon-covered opening, and with the other end of the straw hanging several inches over the edge of the jar. On this end of the straw we attached a small triangle "pointer". I also had them tack the straw with a dab of glue at the edge of the jar opening. Hot glue worked best. It's a good thing...The air inside the jar is now "captured" and is your "control". As the surrounding atmospheric pressure increases, the balloon/diaphragm will be pushed into (concave) the jar. The end of the straw glued to the center of the diaphragm will go down, the lip of the jar will act as a "pivot" or fulcrum, the pointer end of the straw that is hanging over the edge of the jar will go up. Oppposite, when a low-pressure system rolls into town, the diaphragm will be displaced upwards, causing the pointer end to point down. When the barometer was made we made a scale to stand next to the barometer. We indexed the current needle position to "zero" and measured 1/8th-inch increments up and down for about 2 inches in each direction. At the top of the "up" scale they drew a sun, at the bottom of the "down" scale they drew clouds and raindrops.They tracked the weather for two weeks and suprisingly, they were pretty accurate. One girl's readings were way out of line with the others, it was a head scratcher...until she finally fessed up she took the barometer with her on vacation. The control air obviously will affect the accuracy of future up/down readings.We also did (again in 2nd grade) an experiment based on how smell affects taste. With pinched noses (and blindfolded) we fed them a bit of chocolate, a small piece of a section of orange, several different items, and they tried to guess what they were eating. Run through the whole class, then repeat without the pinched nose.Did similar, blindfolded, with them trying to guess scents. Garlic, orange, cinnamon, chocolate, pepper, anise (black licorice), a bar of ivory soap, etc. I got some responses that were much too funny.Also had a bunch of optical illusions. They were fascinated with those.This year they built two roof sections, one vented and insulated with FG batts, the other unvented and insulated with DP cells. We've analyzed most of the data, but haven't been able to come to any real conclusions. Every time I bring up the subject they start name calling and hair pulling. Oh well. Kids...can't wait until they're older and more mature so they can have a serious discussion on it.
*Optical illusions are fun. Here's one place to start: http://members.aol.com/Ryanbut/optical.htmlGoogle on optical illusions for many more.
*Everyone knows a cat always lands on it's feet. In times of crisis they also always head for the highest point around.There is a neat experiment which takes advantage of the latter reflex....Get two cats. Tie thier tails together. Hang them over a clothesline. All the kids will be enthralled at the way the cats both try to climb up each other to get the the 'top'.No, wait. This one probably isn't good for 1st graders either.: )
*Jim, you know, dontcha, that you are now obligated to report in full the results, right? TIA!
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Liquid mercury has no danger to anyone when used in a container to demonstrate surface tensions and bouyancy. It is mercury vapor in the air or mercury compounds that are highly dangerous. The vapor pressure of liquid mercury in a container is so low it needs not be considered. A few years ago a couple of kids got hold of some liquid mercury and shared it with friends. Local "Officals" found out about it after a few weeks and were terrified. They had the hazard control group cleaning the kids and had them tested for poisoning. With all the hoppla none of the kids had measurable amounts of mercury in their bodies and had no illnesses. Even though many of us have played with the stuff with no harm they should not have it unsupervised and it is unharmful to use in demonstrations.
And another thing the acid in coke is much more mild than the acid in their stomachs.
Jim
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I have absentmindly volunteered to head a science day at my 7 yr. old daughter's class. So can we take off the hardhats and don wizards caps and come up with SMALL, SHORT experiments that can be done in a first grade classroom?
thanks in advance
Jim
*Jim, congrats! I know there are tons of sites w/stuff for projects like this, but at that age, I was always fascinated by liquid mercury, and magnets w/iron filings. I'll try to find some sites for you.
*Jim,NO MERCURY! On jobs that have kids I always make crown molding puzzles. I cut pyramid and rosette shapes , 4 pieces make a shape but I include 5 with one wrong piece.You could also do the vinegar and baking soda trick or the hard boiled egg soaked in vinegar getting sucked into the bottle. Remember these?KK
*Try Edmund's Scientific at edsci.com for some ideas, loved their catalog as a kid and still do. Lots of cool toys. Go to their general science section and dont forget to order a catalog.JonC
*"NO MERCURY!"Guess my age is showing all over da place! My RN mom made it very clear that one had to wash one's hands after handling this stuff. But we did experiment with it in grade school, with that admonition. Have the risks become greater? Or just better known?Your crown molding puzzles sound great! And I remember that egg trick, too.
*Try this site, Jim:
*Edmund Scientific has their store about 40 minutes from here. I can spend hours in their surplus room. So much junk saved from the land fill.
*Kai, Nice site. Mercury is a neurotoxin. It can be absorbed, ingested, or inhaled. I can only think of a few adults I would want to play with it but no kids.KK
*Thanks KK for that important, cautionary info re mercury. I guess we used to play with lots of dangerous stuff--in school, no less (and in honors--well, they were called "advanced" back then--classes to boot)--when I was a kid, precautions nothwithstanding. I remember shining dimes with it. Didn't know that one could breathe toxic fumes from just having it in front of you--nor do I think my teachers would have allowed us to touch it (and wash our hands after) if they had known it would be absorbed into our skin.Your post is one of the reasons I really love this medium. Thanks!
*Here are a couple that have been done in my kids' classes:Copper penny cleaning: Corroded pennies, vinegar, salt. Add some salt to vinegar in a small bowl. Add corroded pennies. Vinegar and salt solution removes the copper buildup, "cleaning" the pennies and making them bright and shiney again. The removed copper corrosion is now, simply, copper ions in solution.This brings you to step two: Immersion plating. The only thing extra you need is a 16d or 20d spike. Give it a good rubdown with sandpaper or steel wool to give it a shine. No skin oil. Place it in the vinegar solution. The copper will come out of solution and "plate" the nail, giving it a nice copper color. It happens fast, in 20-30 seconds or so and thus works well for the kids. I've talked about copper vs iron ions, how one is more excitable then another, similar to their classmates (some rowdy, some wallflowers). Some have lots of energy (and want to remain bouncing around in solution) while others are lazy (want to rest, get out of solution and thus "plate" or "rest" on or against something, in this case the nail). Simple language, but they could relate.I've used about 3T salt in 1C of vinegar. Add in about 20 pennies. The more corroded, the better.As a side show, we also cleaned pennies using lemon, coke, ketchup, etc. Another they enjoyed was similar to the celery/food coloring trick. In this one, we used carnations. Slice the stem lengthwise into halfs or thirds (not removing stem from flower), slitting lengthwise. Add food coloring to 2 or 3 glasses of water and place an individual stem section into each colored glass. You'll end up with a mulit-colored carnation. You can talk about cell structure, capillary action, etc.Simple with quick results.The kids will love it. You will to. Have fun.
*Kai;better known.Also, in a one on one, you can watch what's happening. I'd venture the opinion that allowing open liquid mercury in a classroom is reckless. My opinion.I did a science presentation to 2nd graders on surface tension: colored water poured along a string, put water in a cup, up to the rim. THEN add pennies: the water will rise above the rim. Count how many.Now the hard part: explain why without getting into thermodynamics!
*Great Adam. Thanks for that info--I think the string experiment would be fun, but, sheesh, dang my brain, I am not understanding how it works! Must be the tech writer in me :)
*I always thought mercury was cool, too ... and in fact I remember making some in the sixth grade by heating a mercury compound which offgassed pure oxygen.Mercury causes central nervous system damage and is particularly dangerous for developing nervous systems. It happens that inorganic pure mercury is safer than mercury compounds because it is less readily absorbed, but like lead it has been known dangerous for a long long time. (Why do these things take so long to regulate? Let's see, it was used in thermometers, bacteriocide, paint, ... hey, wasn't lead in paint too?) An infamous example is the Minimata Bay disaster in the 50's, where thousands were poisoned by eating fish taken taken from a bay polluted with industrial waste. Because like DDT it is difficult to excrete, the pollutant becomes more concentrated as it moves up the food chain.<a href=http://cerhr.niehs.nih.gov/genpub/topics/mercury2.htmlHere is an NIH piece on mercury (+ other drugs) & children/fetuses.I was surprised that a new electromechanical thermostat purchased by a client contained old-fashioned mercury switches ... these should be treated as hazardous waste. I steered them towards an electronic setback thermostat -- same price -- by White-Rogers which, I was impressed, volunteers to take old mercury thermostats if you have trouble getting rid of them otherwise.From a web source:>Mercury (also known as quicksilver) was named after the fleet-footed messenger of the gods. It is one of the most toxic substances known to humanity, particularly when comined with other atoms and molecules, such as the methyl or chloride forms. These have far greater biological penetration. Brain tissue is particularly at risk. The expression "mad as a hatter" comes from the twitching and dementia once common among hatters, who used to dip felt in mercuric nitrate to soften it.The article focuses on concerns about mercury in dental silver amalgam -- to my knowledge these claims have never been proven despite their persistence for over 20 years. (But I liked the quote.) Here's a piece blasting conventional dentistry. Nothing wrong with thinking it over ... but I have plenty of silver in my teeth without problems. without problems. without problems. without problems. And on poisoning by naturally-occurring mercury, released by deforestation: http://www.idrc.ca/books/reports/1997/19-01e.html
*My aged neighbors remember getting dosed with 'blue mass' every year before school started. They say it came in a tube, and their mothers would work it into a pill about the size of a shooter marble. That was followed by a dose of Epsom salts and several hours in the outhouse. I looked up blue mass, and it's still listed in the Merck index (also as 'mercury mass' and 'blue pill'). It's compounded of 30-40% mercury metal with the remainder consisting of honey, glycerin, and licorice
*Above all, you want to keep the science experiment/demonstration short and simple.I teach college computer science classes, and I'm amazed at the number of students who don't know that you can make a magnet by twisting a wire around a nail and hooking it to a battery. If time permits, you might ask what would make the magnet stronger. Some think that the size of the battery will determine the strength of the magnet ("D" vs. "AA" for example). You can also suggest more wraps of the wire around the nail. Which will pick up the most paper clips? This is very simple but informative.Related: What materials are attracted to a magnet? Try aluminum foil, steel, stainless steel, a nickel, a dime, a penny... You could couple that experiment with the flip-side: a magnet moving past a wire induces current to flow in the wire. Get a 12 to 15 volt DC motor (available at Radio Shack) and hook the terminals directly to an LED. Spin the motor with your fingers and the LED will light up (briefly). This demonstrates how the power company generates electricity for your home.Someone mentioned surface tension. A good demonstration of this is to sprinkle talcum powder or black pepper on the surface of water in a pie pan. Rub your finger on some soap, and touch the water in the pan. The powder will scatter in all directions because the soap breaks the surface tension. A variation on the vinegar/baking-soda demonstration is to mix the two in a container with tall sides (like a drinking glass). The carbon dioxide produced is heavier than air and will hang in the container. Light a match, and slowly pour the carbon dioxide from the container over the match. The match will go out because of lack of oxygen. The effect is neat; pouring an invisible gas out of the container over the match. Have fun....and put your heart into it...
*Air pressure inside and outside of a container. Always was my favorite. Get a square can, like the kind a gal. of thinner comes in. Fill half w/ water. Put over burner and boil out the water. When almost all the water is boiled out screw the top on. The water heats, heats the air inside. Expands as the water boils out. Cap it and the out side air pressure will start to crush the can inward. Very cool. Looks like magic. Jeff
*Jim,my wife teaches first grade.Several times each year the class has a cooking project where the students learn about measuring carefully,mixing ingedients,how baking powder works,all sorts of stuff.Always a huge favorite with the kids,especially the ones who have never eaten anything that wasn't microwaved out of a box.A lot of kids have never seen cookies made that were not sliced out of a tube,and have no idea that bread can be baked at home.A 7 year olds attention span is very short.(your teacher can show you a chart which will pretty accurately gauge the attention span of each age group involved) Some people have suggested some excellent projects here but the time required may exceed a 7 year olds concentration( still good projects for 4 th or 5th graders though.Don't do anything that might be to risky for kids if they tried it un-supervised at home.( A 7 year old with a pot of boiling water is pretty scary)The mere fact that you are a DAD in the classroom will be a big hit.Have fun,Stephen
*Mongo am going to try this at home myself. Takes me back to the days of Mr. Wizard,do you go back that far? One of the best shows for kids( and adults to ever bless the small screen. Skip
*Mongo is really onto something with this "Copper penny cleaning" thing. My boys both did it in preschool, and thought it was great. For months afterwards, they would sometimes ask if they could clean pennies when they were bored. You might ask the teacher if she has any material and/or suggestions. I'm sure this is something that's been done many times in the past, and she might be able to help with what works/doesn't work.
*It's not only a science project, it's also a way to cheaply copper plate a fixture, etc for a client.
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More optical illusions: http://216.240.130.115/optical.htm