Introduce children to the concept of matter by demonstrating how matter takes up space. Fill a clear jar with golf or ping-pong balls. Ask the kids if they think the jar is full. Add small pebbles or rice to the jar, shake the jar and ask them again if they think the jar is full. Add sand to the jar, shake the jar and ask them the same question. Finally, add water to the jar and repeat the question. This simple experiment demonstrates to children how matter can take many different forms and sizes.
Demonstrate to children how the sun's energy can be transferred through sunlight, thus helping them better understand solar devices and solar panels. Take two plastic 2-liter bottles. Remove the labels. Paint one bottle black and the second bottle white. Attach a balloon to the top of each bottle, ensuring that the fit of the balloon around the bottle is airtight. Place both bottles in sunlight. Have the kids observe which balloon inflates and how warm or cool each bottle is to the touch. Explain the effect of color on sunlight absorption.
Hold a strong magnet against a dollar bill to demonstrate the magnetism of a dollar bill, which comes from traces of iron used in the bill's ink. Ask the kids their theory about this magnetism. Place the dollar bill in a blender and add water so that the blender is 1/2 to 2/3 full. Cover the blender and blend the dollar and water for at least a minute. Pour the mixture into a plastic zipper bag and seal the bag. Hold the magnet against the bag and swirl the contents around. Hold the bag upright, allowing the liquid to settle at the bottom, then remove the magnet. Show kids the iron that forms on the magnet and the iron that sticks to the bag once the magnet is removed.
Fill a glass jar half with white vinegar and half with water. Add 1/4 cup to 1/2 cup of baking soda, depending on the size of your jar. You should see bubbles forming as you add the baking soda. Explain to kids how the bubbles are formed by a chemical reaction resulting in carbon dioxide. Drop 10 to 12 raisins into the jar. The raisins will sink at first, then be lifted by the gas bubbles. They will continue to bob up and down as the gas bubbles rise to the surface.