Concept notes coming soon.

Concept notes coming soon.

Concept notes coming soon.

Concept notes coming soon.

Polyacrylamide crystals can absorb over forty times their weight in water and also have interesting optical properties. Students enjoy seeing and learning about their surprising behavior.

If you are studying hydroponics, students can make artificial soil with polyacrylamide crystals and water. Once the crystals have fully expanded, put them in a petri dish and your students can study them with a hand lens. These crystals also have the interesting property that the speed of light through the crystals is the same as the speed of light through water, so they become invisible in water. Once you have shown your students this, dip your hand in to pick up the crystals and show that they are still in solid form.

Old overhead projectors can be used to display microscopic images.

If you are designing a school science lab, you may elect to work with a class set of mounted butane torches or some commercial butane burner and eliminate the expense installing, maintaining and securing gas lines. These options offer a safe, much less expensive source of concentrated heat.

The burners and canned butane fuel can be safely stored in a fire-resistant cabinet and allow the classroom to be safely used for other purposes, such as math lessons or other classes, without the worry of students being tempted to mishandle the gas taps in the absence of a supervising teacher.

Follow the manufacturer's guidelines as to how long the torch may be used in a single experiment. (Some can go for approximately 30 minutes before shutting off for safety.) As always, observe all safety protocol when working with any heat source.

The orange butane torch is advertised inexpensively in tool catalogs and sold through hardware and cooking supply stores. You may purchase canned butane for fuel in hardware stores, newspaper stands, drug stores, camping and hunting supply shops, grocery stores and virtually any shop that sells cigarettes or tobacco products. The commercial burners can be found in a hardware store or marine supply store.

Using the butane torch we recommended earlier, you can make your own custom-made glassware for experiments like fractional distillation.

A water seltzer or bicycle pump with a carbon dioxide cylinder inside is a great source of pressurized carbon dioxide that can be used to demonstrate countless different ideas.

One dramatic experiment you can do to demonstrate the higher density of carbon dioxide gas compared to air, is to fill a large tank, such as a fish tank, with carbon dioxide and blow some soap bubbles on it. The soap bubbles will hover on top of the invisible carbon dioxide layer.

You can also experiment with carbon dioxide and water, adding an indicator to see how the pH changes when carbon dioxide is bubbled through. Bromothymol blue is great to use as it turns a bright yellow. Or, attach a hose or aquarium tubing and pump the carbon dioxide through lime water to produce a precipitate. These experiments can also be done in a fish tank to make for an exciting demonstration for the class.

The carbon dioxide pump can also be used for inflating objects such as basketballs, for physics experiments.

Glasses with a diffraction grating lens can be used as a fun tool for visual and inexpensive experiments about light. Students of all ages can learn about how light from different sources is composed of different wavelengths. For older students this item can be used as part of a more sophisticated lesson in light physics.

Let your students look with the glasses at various different light sources, such as a black light, an infrared light, a full spectrum white light and a light for a photo lab and get them to make a drawing of each spectrum in their science journals and compare the spectra. This lesson can be done with kids as young as first grade.

You can make your own glasses with a piece of diffraction grating material (you can buy some from a plastics company), or buy them inexpensively.

Empty cans, such as recycled coffee cans, are versatile, free and easy to find tools for a science classroom. They can be used for a number of experiments - in these videos we make a sound wave oscilloscope, a pinhole viewer (by putting two cans together), displacement cylinders, an air cannon and a space suit simulator. For more ideas, take a look at this article called "Science in a Can".

Bring them in from home, or, to build up a large set, ask your students to bring some in as their homework. If possible, remove the top and bottom of the can in such a way that no sharp edges remain. Also, when preparing a class set of cylinders made from recycled cans, run the entire set through a dishwasher for sanitation.

Pipe clamps are quite inexpensive, durable, easily fitted into different sizes, and are an excellent way to attach lab sensors and fix lab tools into positions that can be held stable for long periods of time. A collection of the clamps in all sizes is useful to pre-engineer experiments.

One application of pipe clamps is in combination with rare earth magnets, where they can be used to hold and suspend heavier lab equipment into position during experiments.

You may find it helpful to paint the pipe clamps with engine paint to allow them to be more easily sorted into different bins as they are used throughout the year. The stainless steel pipe clamp is one of the most stable, inexpensive and versatile items in the virtual toolbox. Treat yourself to a whole set of them in all sizes.

Experiment with the optical properties of interesting crystals that bend light, such as the "television stone", Ulexite. When viewed through the television stone, newspaper print appears to be displayed on the stone surface, like on a television, for which the stone is named.

Using your miniature laser level and some other types of crystals (such as the polyacrylamide gel crystals), you can test how different crystals bend light and get your students to identify the crystals based on the angle they bend the light. Crystals are usually identified using x-rays but the laser works just as well here and brings the scale of the experiment up to the visible region. You can also do this experiment with different lenses, to see what lens shapes direct light in which directions.

A round hovercraft toy like this one here is a fun way to teach about friction and forces, angular momentum and other ideas open to your imagination.

Paint the hovercraft a solid color and mark an X at the center and an X at the edge and observe how fast each X rotates.

Compare how easy it is to get the hovercraft moving by pushing it in a straight line when it's floating on a layer of air, compared to when it is sitting on a table.

A glow in the dark pigment, such as zinc sulfide, can be used to demonstrate how images can be made with light and a photoactive material.

In a completely darkened room, make a thin layer of the zinc sulfide pigment and then use a flash of light, such as a camera flash, to photoactivate it so that it phosphoresces. You can turn this into a nice demonstration by placing your hand over the layer of zinc sulfide. When you use your camera to photoactivate it, you will see the image of your hand left behind.

LEDs (Light Emitting Diodes) come in all colors in the visible, UV and infrared spectrum. They are very inexpensive and also very small and lightweight, yet they produce a relatively intense source of light. A broad spectrum (white) LED, such as this one on a bendable antenna is a very useful item.

Electrical tape comes in many different colors and is great for labeling kids projects and coding things around the classroom.