Science Demos?

[Jessica]

Anyone have a cool science demo to share? I'm looking for something interesting to show for my observation in a few weeks.

[Unregistered]

Lisa's Hotscakes had a neat demo of the spread of germs in a post recently. It used cups of water for each person in the class with red dye in one cup. The students then were to share the germs by transferring the water amoung the cups. You could search for her post.

[Unregistered]

Make sure the red dye is strong enough so that there is sufficient color in the final cups to be noticable.

But let me put my Lisa H. cap on for a minute: What do your standards say should be taught regarding scientific experiment? That should be the basis of what you do in class for a demo.

[dhom]

I agree with the last post. If it's a physical science class, you can do my favorite demo:

Get 100% acetone (the pure stuff that you have to order through the main), put a little bit in a glass beaker, and start stuffing styrofoam cups in. The students will all be counting the number of cups out loud by the time you're finished. Then you can peel out bits of the remaining goo and let the students take them home. :)

[Unregistered]

I'm not sure about its "cool" level but here goes.

I hold up a piece of paper and have a student come up and tear it in half. Then I ask the class if that has changed the paper. In what way? (hopefully, you get to that it's changed physically and not chemically). Have a few more students, one at a time, come up and tear the paper and keep asking if it has changed yet and how.
Lastly, I put the paper in something fireproof, put it in the fume hood and light it on fire. Let it burn completely. Again, ask has it changed? How? I have found that this gets the point across about the differences between chemical and physical changes.

Good Luck!

[dhom]

You can also burn FOOD to show how effectively food stores energy. I like holding gummi bears above a flame. As they melt and drip into the flame, the flame makes a popping noise and a visible burst. Nuts are fun too because they burn for a long time after being lit with a match.

[Sandi]

Anyone have a cool science demo to share? I'm looking for something interesting to show for my observation in a few weeks.


Run red cabbage through a juicer. Set up a test tube holder with a variety of acid, basic, and neutral substances in each (water, vinegar, ammonia, milk of magnesia, baking soda solution, dye free liquid laundry detergent, etc). Drop several drops of the cabbage juice into each test tube and have students observe the color changes.

[Unregistered]

I want some science damos for 4th class students.

[Instructorus Rex]

Drill a hole through a cork, attach one end of a plastic tube to a bike pump and run it through the hole you just drilled in the cork. Hot glue the end of the cork where the tube exits to make it air tight. Jam the cork into the mouth of a two liter plastic soda bottle and place in a stand so that the end with the cork is facing down and the bottom of the bottle is facing up. Start pumping.

Air pressure will build up inside the bottle until it blows off the cork, the result will be a bottle that will fly for a whopping six inches. Have students discuss what force is causing the bottle to shoot up, then have them hypothesize about what will be the best rocket fuel - 1/4 water, 3/4 water, or 1/4 water + soap.

The 1/4 water & soap works best, the air pressure forces the sudsy water out which propels the bottle upwards at a pretty surprising speed. My best got about 50 feet into the air so needless to say you should probably do this outside.

If you want to get real crazy you can have students add construction paper cones to their rockets and even hot glue on some fins for stability going over how this will affect the forces acting upon the rocket while it flies such as friction & gravity. I happened to be doing this experiment when a team from our school district was observing some of the science classes at our school. . .it left somewhat of a memorable impression.

[Instructorus Rex]

This really only works if you happen to have a laser level. . .but they're not terribly expensive. If you do you can demonstrate refraction by shooting the laser beam through a prism and observing how the light changes direction and splits into several distinct beams of light. Then, if you have them, give each table a small mirror and a piece of modeling clay. Students use the clay to anchor their mirrors to their desks and help you demonstrate reflection. Aim the laser at one desk and have them angle their mirrors so that it bounces off each mirror with the last desk having to aim the light to hit a small target at the front of the class. This can be frustrating as any time someone bumps any one of the mirrors it messes up the whole thing, but students absolutely love this experiment and really get into it. The laser light won't disperse either, so you can bounce it off over ten mirrors and still have a distinct red dot.

[diobiesel]

cellular respiration can be demonstrated by fitting a balloon over a test tube about one-third to one-half full of a yeast solution. Maintaining the test tube upright, the balloon inflates with produced carbon dioxide gas.

[Instructorus Rex]

Drill a small hole in the lid of a plastic bottle. Pour in a tiny amount of rubbing alcohol, cover the hole with your finger and shake the bottle to stir up some alcohol fumes. Then place the bottle on a ramp and hold a lit match up to the hole (after, of course, removing your finger). The match will ignite the alcohol fumes inside the bottle forcing all that expanded hot air and unburned alcohol out the small opening and propelling your rocket forward. It's also going to make a lot of noise and smell bad. My class measured the difference in distance depending on the size of the hole due to the changes of pressure. It's also fun to use a milk carton for this and attach an axle and wheels to make a rocket car! Oh, and try it once with the lights off; the ignited alcohol fumes inside the bottle look pretty sweet.

[rah07]

Hi,
The step taken forward by the person is good. He has really done a hard work.


Joe

[Lynna Lucia]

I need ideas for science demos for my science class. They need to be under 10 minutes long and safe for middle school to do. If you have any useful ideas or suggestions of demos or websites I could use, please answer. Thank you.

Wound Care Products (http://www.woundhoney.com/Wound-Honey-by-ERAS-Natural-Sciences-1-80g-Tube-p/wh-01.htm)

[Unregistered]

Go to http://blogs.scholastic.com/classroom_solutions/stacey_grades_68.html and see the ideas that Stacy has for science in her middle school classroom. She has loads of pics showing what her science looks like. She also writes a blog so you can pick her brain for ideas for your specific classroom.

[Unregistered]

How do i show diffraction in a science demo?

Fire science universities (http://www.cogswell.edu/FireScience.html)