22 December 2015

11 Fun Science Experiments That Actually Worked

I am not one of those cool homeschool moms who comes up with awesome hands-on fun every day. I am more of a thank-goodness-my-kids-like-reading-as-much-as-I-do kind of homeschool mom.

But, every once in a while, especially when it comes to science, seeing is believing. While several science experiments we’ve tried over the years resulted in epic fails, the following ones actually worked and amused the Agents.

For each one I’ve included supplies, directions, what {should} happen, and the simplified explanation {my audience is ages 5-9} of the scientific principle it illustrates.

{Note: I could only find photographic evidence of two of these experiments. Clearly I need to document our science lessons better. Sigh.}

Naked Egg

What you need: raw egg, vinegar, glass {wide and deep enough for the egg to be completely covered}

What you do: Put the egg in the glass and pour vinegar over it until it is submerged. Let it sit for 24 hours. Carefully change the vinegar, and let the egg sit for another 24-72 hours.

What happens: The egg shell disappears, leaving you with a translucent, yellowish membrane {and a slightly bigger, bouncier egg}.

What it illustrates: The acetic acid in the vinegar dissolves the calcium carbonate shell. Some vinegar also permeates the egg, increasing its size {osmosis}.

Poofy Soap

What you need: fresh bar of original Ivory soap, wax paper, microwave

What you do: Lay the bar of soap on the wax paper in the microwave and “cook” for 60-90 seconds.

What happens: The molecules of air in the soap move away from each other and the soap “grows” into a big puffy cloud.

What it illustrates: Gases expand when heated. {Charles’s Law}

Crashing Colors

What you need: whole milk {yes, it has to be whole; you need the fat for this to work}, food coloring {liquid, not gel, in blue, yellow, and red}, shallow bowl, dishwashing liquid

What you do: Pour the milk in the bowl until it covers about one inch. Place a drop of each color of food coloring as far apart from each other as possible {making a triangle}. Do NOT mix or bump the bowl. Place a few drops of dishwashing liquid right in the center of the bowl.

What happens: The colors begin to move and swirl into each other.

What it illustrates: The detergent weakens the surface tension of the milk so the food color molecules are free to move around.

Floating Egg

What you need: 2 glasses, 2 eggs, water, salt, spoon

What you do: Fill both glasses with water. Add 3-4 spoonfuls of salt to one of them. Carefully place an egg in each glass.

What happens: The egg in the plain water sinks to the bottom, but the egg in the salt water floats.

What it illustrates: The salt increases the density of the water, making it greater than the density of the egg, enabling the egg to float.

Oil and Water Don't Mix

What you need: empty water bottle, cup, water, cooking oil, food coloring

What you do: Fill the water bottle halfway with oil. Fill a separate cup with water and add a few drops of food coloring. Add the now-colored water to the bottle until it’s full. Cap tightly and turn the bottle upside down and side to side.

What happens: The oil and water mixtures stay separate, with the oil settling on top no matter what direction you turn the bottle.

What it illustrates: Oil and water molecules don’t mix, and oil has a lower density {hence why it “floats” on the water}.

Diffusing Colors

What you need: 2 same-size glasses, cold water, hot water, food coloring

What you do: Fill one glass with cold water and fill one glass with hot water. Add a drop of food coloring to each.

What happens: The food coloring moves through the hot water faster.

What it illustrates: Temperature affects the rate of diffusion.

Make Your Own Goo

What you need: shallow pan, cornstarch, water, food coloring {optional}

What you do: Add some cornstarch to the pan {maybe 1/2 cup to start}. Slowly add water {you’ll need less than half the amount of cornstarch} and mix. Add food coloring if desired.

What happens: As you manipulate it, the texture of the mixture seems to change from liquid to not quite solid and back again.

What it illustrates: Properties of a suspension {the cornstarch—a solid—is dispersed in the water—a liquid}.

Expanding Balloon

What you need: empty water bottle, funnel, vinegar, baking soda, balloon {not inflated}

What you do: Use the funnel to add approximately 2 tablespoons of baking soda to the balloon. Pour roughly 1/2 cup of vinegar into the bottle. Carefully turn the bottle to the side, and without letting the baking soda fall into the bottle, secure the balloon on top. Tilt the bottle back up to a standing position.

What happens: The balloon inflates.

What it illustrates: The baking soda {a base} and vinegar {an acid} react to produce the gas carbon dioxide, which expands and fills both the bottle and the balloon.

Card Trick

What you need: glass, water, card big enough to completely cover the opening of the glass {something thicker than paper but thinner than cardboard, like an oversized playing card or index card}

What you do: Fill the glass with water and place the card on top. Keeping your hand on top of the card, gently turn the glass over. Remove your hand from the card.

What happens: The water stays in the glass. {Confession: I still do this one over the sink every time.}

What it illustrates: Air pressure—the pressure of the air outside the glass pushing up on the card is greater than the weight {pressure} of the water inside the glass pushing down.

Invisible Skin

What you need: cooking oil, running water, soap

What you do: Pour a little oil over your hands and massage it in well. Once your hands are coated, try rubbing your hands together under running water. Add soap and try rubbing them under running water again.

What happens: The water rolls right off your oily hands, but once you add the soap the oil comes off and your hands are clean.

What it illustrates: Oil and water molecules don’t mix, but the soap molecules are attracted to both.

Flying Tennis Ball

What you need: a basketball, a tennis ball, an outside location with a hard surface that is free of obstacles

What you do: Stand holding the basketball with tennis ball centered on top of it and release both together.

What happens: The basketball bounces a little, but the tennis ball flies way up into the air.

What it illustrates: Energy transfer—the kinetic energy in the basketball is transferred to the tennis ball.

No comments:

Post a Comment