When students learn about the Solar System they have a difficult time visualizing or comprehending what the distances are like between the planets and the sizes of the planets and the Sun. Most textbooks show pictures of the planet on one scale and the distances between the planets on another scale. They never have them to the same scale. The reason why is that the Solar System is huge! There are a ton of Solar System scale model lessons on the web. One of the best is the half mile long model. In this model the following represent the planets (see slide show): Mercury, Mars, and Pluto = head of pin, Earth and Mars = peppercorn, Jupiter = rubber ball, Saturn = hazelnut, Uranus and Neptune = peanut, Sun = volleyball. I glued these items (except the volleyball) to paper plates. I then made a flag for each planet out of wooden dowels and construction paper. I then inserted the flags through the middle of the paper plates and set the combination into a PE cone (see slide show). The distance between the planets are on the teacher handout (students have a separate handout). I have my students record into a lab composition book a journal of their tour. They answer questions before, during and after the tour. They are pretty amazed by the size of the model (see slide show). You need to have a pretty straight stretch of street (see slide show) to use, that isn’t too busy. I give my principal notice ahead of time and I also bring a first aid kit.
This is from a terrific site, Steve Spangler Science. I do many density demos and lessons and I am going to try this one this year.
“ProjectsFizz, Bubble, Erupt! Learn how to make an inexpensive science toy that will be a guaranteed hit with the kids! Ok, so everyone knows that oil and water don’t mix. Try adding a few drops of food coloring and a little Alka-Seltzer fizz to the solution and the bubbling concoction is guaranteed to provoke a few ooohs & ahhhs!”
Many of the demos that I use in teaching chemical reaction are taken from a terrific book called A Demo A Day–Chemical Demonstration Book. The book contains a year’s worth of chemistry demonstrations that are easy to follow and to use. This demonstration shows that when iron has a large surface area it can react with oxygen and burn easily. I first use the 9 volt battery and touch the ends to various steel surfaces. The students see that nothing happens. I then touch the battery to the steel wool (held by the clamp on the ring stand) and the battery provides enough energy to make the iron burn. The steel wool has a larger surface area than pieces of steel like the ring stand. The steel wool is exposed to more oxygen molecules. You can also use this as a conservation of mass demo. Simply place the steel wool in a plastic bag and measure the mass. After burning the wool (of course it shouldn’t be in the bag at this point) return the leftover material back in the bag and mass it again. The mass should be the same (although it might be greater afterwards, since oxygen has now bonded with the iron.).
Preparations: You may have to soak the steel wool in acetone for 15-20 minutes to remove the outer coating, so that the steel is exposed. Take the wool out of the acetone and left it air dry.
Many of the demos that I use in teaching chemical reaction are taken from a terrific book called A Demo A Day–Chemical Demonstration Book. The book contains a year’s worth of chemistry demonstrations that are easy to follow and to use. This demonstration shows the concepts of polymers. Styrofoam is an example of a polymer. A polymer is made up of monomers. You can think of a monomer as a Lego piece. When you connect the Lego pieces together you have a polymer. You can take a Styrofoam cup and place it in a petri dish of acetone. Push down on the cup and the cup seems to disappear! The acetone is breaking the bonds between the monomers.
Precautions: Acetone is flammable and needs to be used in a well ventilated area. Wear goggles.
Watch the Google video.
This is one of the few times that students have an opportunity to touch what an object in the Solar System is kind of like. This demo is very popular and can be found all over the Internet. The materials that are needed are shown in slide show (plus 2 large cups of water). Mix the water, sand, 1 tablespoon of corn syrup, and a dash of ammonia into the bowl (see slide show). These are the main ingredients of a comet. Of course the temperature needs to be decreased dramatically. Dry ice, frozen carbon dioxide, will do this and is also an ingredient. The dry ice needs to be placed into the double heavy duty trash bags (see slide show). Use the hammer to crush the dry ice into a powder (see slide show). Then carefully pour the dry ice into the plastic bowl (see slide show). Using the gloves shape the mixture into a ball (see slide show). Carefully remove the comet and let students touch it. The comet really is the nucleus of the comet–the solid part. Explain to the students that the Sun’s energy heats up the ice to form the gaseous coma, which can be seen in this demo.