Kids Experiments

What can kids learn from experimenting with a carrot?  Try these simple experiments.

Also, you must try Mr Carrot Head - Make a unique face to keep! Click here.

No1 - Get to the root

What You Need:

3 Carrots;  Sharp knife; Cutting board; Glass; Water; Red food colouring

What You Do:

Experiment No 1

1. Fill a glass half full with water.

2. Cut the end tip off of a carrot. Ask an adult to help you!

3. Put the carrot in the glass of water.

4. Put the glass near a window that lets in sunshine.

5. Watch the carrot for a few days.

What Is Happening

The carrot itself is really what we call a "taproot." This is a big and main root that grows straight down into the ground. Along its sides, little roots grow, too. Some trees, plants and bushes have a major taproot; others do not. Roots are really important! They hold a plant in place when it is windy. They keep soil around the plant . And most of all, roots conduct water from the soil up to the plant.

Root No 2 - absorption

Experiment No 2

1. Repeat the first experiment with a new carrot, but this time put 10 drops of red food colouring into the glass of water.

2. Put the carrot in the water for several days.

3. Put the carrot on the cutting board and with the help of an adult, cut the carrot in half. Look inside. You will see red colouring in the tubes of the carrot that go from the bottom to the top of it. This shows you that water was being absorbed by the bottom or tip of the carrot and traveling up the inside of the carrot. This is how plants and trees get water from their roots.

Root cross section

Experiment No 3

Repeat this same experiment but this time cut the carrot in a cross section. Then you can look at how the carrot is structured from that point of view.

What Is Happening?

Radishes, beets, turnips and parsnips are also taproots. You might want to get some of these and cut them to see how they are made. It also is interesting that we eat many taproots! Try steaming, baking or eating these taproots raw! As you think about plants that we eat, check out which veggies we eat that are the stem parts, the leaves, or the flowering part of the plant. Some plants, stems, roots, taproots and flowers are delicious!

Salty Cells

Experiment No 4

Take one large carrot, 3 tablespoons of salt, two glasses, string and water.

What to do:  Fill the glasses half full of warm water. Dissolve the salt in one of the glasses.

Snap the carrot in half and wrap the exposed end with string and tie in a knot.

Place the cut and tied end of the carrots, one in each glass. Leave them overnight. the next morning tug on on the strings to check te size of the carrots. One will have shrunk and the other bloated!

What is happening?

Carrots are made from cells and they are a lot like human cells, little water balloons. The cell walls are the membranes. On one side of the membrane there was water and a lot of salt. On the other side was the cell's water. The only way for saltiness to be balanced is for water inside the cells to move through the cell wall to the salt water to make it weaker - less salty. But there is too much salt in the salt water for the water on both sides of the membrane to ever be balanced, so the cell loses its precious water, collapses and croaks.

If we put our human cells into the salty ocean, the water inside the cells would move right through the cell walls out in to ocean water. Those cells would shrink and die. It's all because the saltiness on one side of the cell wall has to equal the saltiness on the other side.

Note: Cooks will add a pinch of salt to the water when cooking vegetables because there is a tiny bit of salt in the vegetable cell walls. This makes sure the vegetables do not lose  their flavour in cooking.

Make a Carrot Pump

What You Need:

A clear glass or plastic cup; A small carrot that will fit inside the cup; A clear plastic straw; Four toothpicks; A candle; A few drops of ink or food colouring (optional)

What To Do:

1. Scoop the leafy top out of the end of the carrot, making a small hollow.

2. Cut a 5 cm length off the end of the plastic straw.

3. Push the piece of straw into the hollowed-out end of the carrot.

4. Light the candle and use melted candle wax to seal the piece of straw onto the carrot.

5. Push the toothpicks into the top of the carrot, spacing them evenly.

6. Fill the cup with tap water, almost to the rim.

7. Suspend the carrot in water, resting the toothpicks on the rim of the cup.

8. Leave for a day or two and watch what happens.

Can you guess what's going On?

When a carrot grows in the ground, its cells transfer the water in the ground up to the stalks and leaves above ground by a process called osmosis. You can see osmosis at work in this activity. Osmotic pressure has pushed water up into the straw. Osmotic pressure is a kind of pump for plants, helping water to move across cell walls.

Carrot veins

Try this one as well:

Colour the water with ink or food colouring. After the water has risen in the straw, cut the carrot in half. What do you see? Is the ink spread evenly throughout the carrot, or are there main veins? What could the other parts of the carrot be for? Are they coloured at all?

Try putting limp carrot sticks in fresh water. What happens? How long does it take them to become to become stiff again?

Fun Plants

(a) - Easy Peasy - Cut the top off a carrot leaving about 1/2 inch of the orange part and the same amount of green stems if the carrot has already started sprouting from the top. Press the carrot piece into damp sand or soil in a saucer or bowl. Just put a little water into the dish if sand/soil are not available. Soon pretty leaves will appear and hey presto you have a nice plant to keep at a window in bright light.

(b) - A Touch harder - Cut off the stems in the same way, but remove only 2 inches from the tip of the carrot itself. Now hollow out the carrot. You may need help with this, and the next part which gets the carrot ready for hanging down. Stick three strong pins into the carrot bottom to attach string to each. Attach the three strings so that you can hang the carrot from where they are tied together. Keep the hollowed out carrot filled with water. Soon the stem will start to grow from the bottom. Very soon they will curl up around the carrot to make a ferny hanging plant. Great fun for kids.

(c)  The Hanging Carrot Garden

For this you need: Large carrot, Knife , Absorbent cotton, Water, Dish, Wooden skewer , Potato peeler, Thread.

Cut a section about 2 inches from the top of the carrot. Leave any leaves or stalks attached. Stand the cut end in a dish of water on top of the absorbent cotton.

Once shoots have sprouted, remove and scoop a hollow bowl into the end of he carrot using a potato peeler. Push the wooden skewer through the top half of the carrot. Tie the same size length of thread for each side of the skewer. Hang the carrot up in a sunny window and fill the inside "bowl" with water. The shoots will grow up to the light, and you will soon have a hanging garden!

Carrot Imprint

Sensitized photosensitive persons, of which there are quite a few in the world!! may get an exact reproduction of the carrot leaf by placing it on the skin for awhile, followed by exposure to sunshine. Try it and let us know.

How to grow a giant carrot

You should always "dig in" any giant vegetable deep with lots of organic matter, take extra care over feeding, watering and pest control and, if showing, harvest at the very last moment for freshness.

Fill a 6in-wide 4 foot long drainpipe with clean fine sand. (Always be optimistic). Make a hole in the sand with a long pole and fill it with good potting compost. Sow three seeds in the compost and thin to the best one when they have germinated.

Water from the top for the first two months and thereafter from the bottom to encourage the roots to seek out moisture. At harvest time wash out as much sand as possible using a hosepipe before very gently pulling up the carrot. If you pull too hard you may damage the long tapering root.

Hunkins Experiments

Here is an example of Hunkins fine work. For more examples see the web site. Click here.

Make a Carrot Battery

This activity uses a common carrot and two different metals to make a enough electricity to run a small digital clock.

Materials: Two Large Raw Carrots; 2 Pennies; 2 Large Galvanized Nails; 3 pieces of 6" long wire; Small Digital Clock (Tandy (Radio Shack) or Maplin - "Stick-on Timer" £3.50/ $4.99.

The digital clock can be extracted from an inexpensive alarm clock or it can be purchased from an electronics store.

Slice of about 1 inch from each carrot and discard. Place the remaining pieces next to each other, flat face down on a plate.

Strip off about 2 inches of insulation from both ends of each wire.

Wrap one end of one wire around one of the nails. Press the nail into one of the carrots pieces.

Wrap one end of another wire around one of the pennies. Do this by first laying the penny across the exposed wire. Position the penny so it is centered on the wire and almost touching where the wire insulation begins. Fold the end of the exposed wire over the top of the penny. Pinch the penny and wire between your index finger and thumb on one hand and pinch the overlapping wire with the other hand. Twist the penny until the wire tightens around the penny. Press the edge of the penny about half way into the other carrot. You could drill holes in the pennies to make it easier to attach the wires.

Attach one end of the third wire to the nail and the other end to the penny. (see photo below)

Insert the nail into the carrot that already has the penny stuck into it then stick the penny into the carrot that already has the nail stuck into it.

Pop the back off the timer and remove the button battery

Connect the two wires coming from the potato battery to the contact on the battery holder. If the clock does not illuminate the polarity (+ / -) might be incorrect. Touch the wires to the opposite contacts on the timer's battery holder.

How does it work?

The carrot contains phosphoric acid. This acid causes chemical reactions to occur at each of the electrodes (galvanized nail and copper penny). The reaction at the copper electrode strips electrons from the copper and attaches them to the Hydrogen ions (2H+) in the phosphoric acid. This depletes the electrons on the copper electrode which makes if "hungry" for more. The process creats Hydrogen gas.

The galvanized nail provides the Zinc needed for the other reaction. The reaction at the galvanized nail dissolves the Zinc. The dissolving process strips electrons from the Zinc atoms. The liberated electrons stay on the electrode and the resulting Zinc ions (Zn++) migrate into the acidic juices of the potato. This results in an excess of electrons on the Zinc electrode. If a wire is connected between the Zinc nail and the copper penny, electrons will flow. This flow of electrons is the electrical voltage.

When the battery was to an oscilloscope and measured a voltage of 0.5 Volts. Several carrot batteries can be connected in series to generate a higher voltage. The experiment also works (better!) with potato.

Swallow a Goldfish

Swallowing a Live Goldfish! (The Secret).

You're not going to believe the method. It's so ridiculous, but it works! What you need:

One carrot.  One goldfish bowl nearby. Cut up the carrot and carve out a small fish-shaped piece about an inch-and-a-half long.

Really. (Yeah, that's how it's done!) Place the carrot-fish in your coat pocket and wait for an appropriate moment.

The Performance: It's all a gag, really. Just ham this up... When the right "moment" presents itself, palm the carrot in your hand. Since no one has a clue what you are preparing to do, don't try to make a "move" of this, please.

Then, roll up the sleeve, plunge the hand into the gold fish bowl, pull out the "fish" by the tail, hold it up and wiggle it, pop it into your mouth and partake of the "meal". (Expect some very unusual reactions to this stunt.) Then, just step over the bodies of those who've fainted as you dab the corners of your mouth with a napkin!

Please note: If you plan to do this, please do it wisely. This is a very powerful gag and may sicken some persons in the room. Also, be sure that it's not a tank of piranha that have been fed some goldfish that are just waiting to be eaten!

Which floats Carrot/Apple?

Carrot Magic for School Children

Perform a little science magic with this simple experiment. You will need a large bowl of water, a carrot and an apple. First, ask the children what they think will happen when an apple or a carrot is put in the bowl. Place the carrot in the bowl first; then remove it and place the apple in the bowl.

What happens? Why?

Explain to the children that foods like carrots and apples vary greatly in the amount of air they contain. Carrot matter is packed very tightly and is very heavy, making the carrot sink. The apple is not packed as tightly and has many air spaces, which allow it to float.

Try slicing the apple and carrot for more observation.

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