Really Easy and Quick Science Demonstrations

Teaching science is enhanced when students have high-interest teacher demonstrations that make important science facts easier to understand.

1. Point: heat is the movement of molecules

 Procedure: put 400 ml cool water (50 F) in a beaker and an equal amount of 100 F in another beaker. While students watch, put one or two drops of food coloring into each. The food coloring in the warmer beaker will diffuse through the beaker with warm water within minutes due to the faster motion of the molecules.

2. Point: to see how colors mix to make difference colors

Procedure: cut a strip of paper towel about one inch by 12 inches. Using a blue water soluble maker (E.g.: Vis-à-Vis) and make a dark mark about one inch from one end of the strip. Suspend the paper towel in a beaker of water so that it just touches the water below the blue mark. As the water is soaked upward by capillary action, it will separate the different colors in the blue dye and move them slowly up the strip. Allow 5 to 10 minutes for the separation. Blue works best, but green and read are interesting as well.

3. Point: Effect of evaporation on cooling

Procedure: wrap the bulb of a lab thermometer in a single ply of toilet tissue. Wrap around only one or two times and wet the tissue. Note the temperature of the air in the room before beginning. Gently wave the thermometer around or back and forth, stopping every 15 seconds or so to note the temperature which should drop as water evaporates and cools the bulb. This works well when the air is dry (humidity < 50), but will usually produce results inside on any day. After two or three minutes the temperature will level off. Compare on a rainy day and the temperature drop will be less. Students can do this as a simple experiment.

4. Point: How density affects buoyancy

Procedure: pour a clear carbonated drink (like Sprite) carefully into a clear, tall drinking glass. Add about 10 fresh raisins. Initially, the raisins will tend to sink because they are denser than the drink, but as bubbles of carbon dioxide attach to the raisins, they reduce the density and cause the raisins to float to the top. The bubbles will burst at the surface and the raisins will sink again. This will continue for several minutes until the carbonation (CO2) has been lost.

5. Point: demonstrate magnetic field

Procedure: Use ceramic neodymium magnets to show how magnetism can penetrate matter. A small pair of can be obtained at stores like Walmart, some tool outlets, Radio Shack, etc. They are strong enough to separate iron from cereal (like Total) after cereal has been mashed to crumbs and added to water in a Ziploc bag. Hold the magnet against the outside surface of the mixture and tiny particles of iron will be attracted to the magnet. Neodymium magnets of about one cm diameter have a magnetic field strong enough to allow one to be placed on the back of the hand and hold on to another one on the palm of the hand. Be careful! They can snap together with such force that they can pinch! 

6. Point: The "sound" of contracting air (best in cold weather)

Procedure: Have students collect two-liter soft drink bottles -- with caps-- until each student can have one bottle for the demonstration. On a cold day -- 45 F or colder outside -- have student screw the caps on the empty bottles and walk outside. As the cold air outside cools the air in the bottles, the air in them will contract causing outside air pressure to push the sides of the plastic bottles inward creating "crackling" sounds. The contraction of the bottles will be visible as dents. When they return to the classroom, the effect will be reversed and the bottles will expand. Be sure students screw the casps on tightly.

7. Point: Observing with the ears

Procedure: Students often think that observation is done with the eyes only. Place a common object (paper clip, rock, coin, key, etc). Conceal the object in a small box or can. Ask students to try to identify the object by the sound it makes when the container is shaken or gently rotated. Call attention to the types of clues they are using to make their conclusions.

Science Facts for Elementary Teachers

The gray color in this cloud is caused by a shadow.

Elementary teachers will find these science facts useful for enrichment and for addressing common topics that students often ask.  

Events in the world are often not as they seem. Science teachers armed with facts that clarify and inform inspire learning by making science more relevant. 

Weather Facts

Clouds are white, not gray. The gray appearance is an illusion created by lighting and shadows. Parts of clouds in the shade appear gray. The same effect can be demonstrated by projecting light from an overhead projector on a white screen. Holding the hand in front of the screen produces a shadow and an apparent change to gray color, but people know the screen is white, no one “sees” it as gray.

Snow is rare at the South Pole. About 1 inch of snow falls on the South Pole in a year — this is approximately equal to 0.1 inch of rain in water equivalent. The extreme cold prevents water vapor from entering the air in large amounts. When snow falls it stays, blows around and accumulates. Snow depth has reached nearly three miles over inland regions over millions of years.

Don’t open windows to equalize pressure if a tornado is expected! Tornadoes do have low pressure, but it is the savage wind that causes the destruction. Winds in a tornado can reach 300 mph and commonly exceed 200 mph. Opening windows simply invites these winds into the house with less resistance.

Physics Facts

Tires do not have treads to increase friction. Treads provide channels that let rain flow from beneath the tires so that contact with the road is maintained and the car does not hydroplane. A slick or tread-less tire is used on racing cars to actually increase friction. Electric fans don’t cool the air; they cool people by speeding up evaporation of moisture from the skin. The fan motor actually adds a bit of heat to the room. There is no need to leave the fan running if no one is in the room.

The sound of snapping fingers is made when the middle finger strikes the base of the thumb at a high speed. The sound does not come from an interaction between the thumb and finger. The thumb allows potential energy to be stored briefly by holding the finger. Place a piece on cotton at the base of the thumb and the impact will be softened preventing the “snap.”

Earth and Space Science Facts

The total amount of gold ever mined from the Earth could fit into a cube about 60 feet on each side. That’s about equal to filling two Olympic swimming pools. Gold, by the way is very dense. A cube of gold 15 inches on each side weighs a ton — 2,000 pounds!

Sunspots are not black. They only appear to be so because they are contrasted against the brilliance of the Sun’s photosphere. If it were possible to look directly at a sunspot away from the Sun, it would still be bright enough to harm the eyes.

The Earth’s tectonic plates are still moving. The distance between South America and Africa is increasing about as fast as fingernails grow — two or three cm. a year.

Chemistry Facts

Oxygen does not burn. It supports combustion. A spark in a pure oxygen environment will not result in an explosion. Objects burn better in the presence of oxygen as it combines chemically. More oxygen increases the intensity and heat of the fire, but the oxygen is not burning.

The atoms of one object cannot touch the atoms of another. Pushing against a wall may bend the fingers, but that is due to the electromagnetic repulsion of the electrons. Atoms can get very close, but they do not touch.

Atoms are mostly space. A scale model of a hydrogen atom is basic — one proton and one electron. Using a soccer ball as the proton in the nucleus, the single electron would be the period at the end of this sentence ten miles away.

Information like that above helps students understand the world as it truly is — often beyond our perception. The Internet is rich with similar science facts. Teachers can offer questions based on the preceding facts as a topic for an information “scavenger hunt" in the school media center.

Plus... One Really Easy, Fast, and Relevant Science Project!  (

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