Try this at home!
As a science educator, there is nothing better than knowing your students or even children you have briefly met at a science show are trying science experiments* at home. So I hope to add new experiments and activities to this page now and then. Let me know things go. If I know that people are trying out the activities, I will post more ideas, more often.
(*I use the word "experiment" in the colloquial sense - I do understand what a true experiment is, of course)
(*I use the word "experiment" in the colloquial sense - I do understand what a true experiment is, of course)
Painting With Colour and Light - Try This!
I am breaking the rules of this page. Normally I only post activities for which you would probably have the ingredients in the kitchen or would be able to easily obtain them at a grocery store. I am making an exception as this is a truly breathtaking activity.
Step 1: Get two black lights and set them up in a room that can be made completely dark. It is best if the two lights are facing each other with enough space for a plate to fit between them. If you have only one black light, shine it down at the plate.
Step 2: Cover the top of a plate with 1 to 1.5 cm. of shaving cream (half an inch). Squeeze out a little of each colour of body paint onto the top of the shaving cream. Cover the shaving cream/body paint with a thin layer of more shaving cream. You need to use just enough to completely cover the paint.
Step 3: Put the plate between the two black lights. Turn off the light and turn on the black lights.
Step 4: Stir the shaving cream until light starts to appear and keep stirring until you have exposed all the colours you squeezed into the middle layers. Observe how the colours mix together. Keep stirring if you wish.
The Science: The body paints absorb ultraviolet light which is not visible to the human eye. The paints emit this light as visible light giving the fluorescent substance a colour that can only be seen when it is exposed to UV light. When you stir the shaving cream, the body paints are exposed and they appear very bright due to releasing visible light in a dark room.
Have fun.
Step 1: Get two black lights and set them up in a room that can be made completely dark. It is best if the two lights are facing each other with enough space for a plate to fit between them. If you have only one black light, shine it down at the plate.
Step 2: Cover the top of a plate with 1 to 1.5 cm. of shaving cream (half an inch). Squeeze out a little of each colour of body paint onto the top of the shaving cream. Cover the shaving cream/body paint with a thin layer of more shaving cream. You need to use just enough to completely cover the paint.
Step 3: Put the plate between the two black lights. Turn off the light and turn on the black lights.
Step 4: Stir the shaving cream until light starts to appear and keep stirring until you have exposed all the colours you squeezed into the middle layers. Observe how the colours mix together. Keep stirring if you wish.
The Science: The body paints absorb ultraviolet light which is not visible to the human eye. The paints emit this light as visible light giving the fluorescent substance a colour that can only be seen when it is exposed to UV light. When you stir the shaving cream, the body paints are exposed and they appear very bright due to releasing visible light in a dark room.
Have fun.
Glow in the Dark Eggs for Easter*
*This won't actually be ready in time for Easter.
I must admit, I haven't tried this yet. But it looks amazing and it sounds easy, so I am posting about it.
Materials: a raw egg, a highlighter (a neon coloured one), a glass jar, vinegar, a hammer, a black light (novelty shops have these)
Step 1: Break the highlighter with a hammer (Kids, get a parent to supervise). Separate the felt of the highlighter from the plastic and put the felt in a jar with 125 ml of vinegar.
Step 2: Squeeze out the felt until most or all of the colour is out of the felt and has gone into the vinegar. Remove the felt.
Step 3: Put the egg into the jar and add enough vinegar to completely cover the egg. Leave the egg for one week. The shell will dissolve, but the egg will hold together. It may only take a few days, but check it before you take the egg out of the liquid.
Step 4: After a week, remove the egg from the jar and examine it under a black light in a dark room.
The Science: The vinegar reacts chemically with the calcium carbonate in the egg shell. The shell is completely dissolved. The colour is absorbed into the egg. Neon colours seem bright because they absorb ultraviolet light (that we can't see) and release it as visible light (that we can see). The black light makes ultraviolet light and the colour from the highlighter turns that into visible light so the egg glows.
*In case it isn't obvious, please don't eat the egg.
I must admit, I haven't tried this yet. But it looks amazing and it sounds easy, so I am posting about it.
Materials: a raw egg, a highlighter (a neon coloured one), a glass jar, vinegar, a hammer, a black light (novelty shops have these)
Step 1: Break the highlighter with a hammer (Kids, get a parent to supervise). Separate the felt of the highlighter from the plastic and put the felt in a jar with 125 ml of vinegar.
Step 2: Squeeze out the felt until most or all of the colour is out of the felt and has gone into the vinegar. Remove the felt.
Step 3: Put the egg into the jar and add enough vinegar to completely cover the egg. Leave the egg for one week. The shell will dissolve, but the egg will hold together. It may only take a few days, but check it before you take the egg out of the liquid.
Step 4: After a week, remove the egg from the jar and examine it under a black light in a dark room.
The Science: The vinegar reacts chemically with the calcium carbonate in the egg shell. The shell is completely dissolved. The colour is absorbed into the egg. Neon colours seem bright because they absorb ultraviolet light (that we can't see) and release it as visible light (that we can see). The black light makes ultraviolet light and the colour from the highlighter turns that into visible light so the egg glows.
*In case it isn't obvious, please don't eat the egg.
Just in time for Christmas
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I clearly don't post very often (sorry).
Here's a fun winter science activity. It's especially important for those snow-starved Victoria kids to get a chance to make snowmen. Materials: a big bowl, a cookie sheet, a can of shaving cream (foam not gel), orange and black cardboard (plastic works), a box of baking soda, vinegar, blue glitter Step 1: Pour most of a box of baking soda into a bowl and add blue glitter. Mix. Step 2: Add shaving foam and mix well with the baking soda and glitter until you have a texture similar to snow. It should hold its shape. I am choosing not to give you specific quantities due to differences in shaving foam. Add more foam if too powdery and add more baking soda if too foamy. Step 3: Kids can make snowmen or snow forts or their favourite scene from Frozen. Don't suggest snowballs. I cut orange and black cardboard to make the snowman's nose and eyes. Feel free to grow tiny carrots and dig for tiny pieces of coal for this activity. Step 4: Pretend to be an evil genius out to destroy snowmen and add vinegar to snow creations. It does not end well. |
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The Science: The chemical reaction of vinegar and baking soda is well known. Vinegar is also known as acetic acid (CH3COOH) and baking soda is sodium bicarbonate (NaHCO3). They have an acid base chemical reaction producing carbon dioxide gas (CO2) and some other stuff, of course.
Just in time for Easter - "tie-dyed" Easter eggs
On Wednesday, my students chopped up silk ties and transferred their patterns to Easter eggs. Here are the instructions:
Materials: vinegar, 100% silk ties, cotton (t-shirt material works), string, a glass or enamel pot (I have used stainless steel and it worked too), vegetable oil*
Step 1 Cut up silk ties or silk scarves into pieces big enough to easily cover the surface of the eggs. Cut up the cotton into pieces also large enough to completely cover the eggs
Step 2 Wrap the silk around the egg so the egg is completely covered and so the darkest part of the silk is touching the egg shell. Now wrap the cotton tightly around the egg and silk to hold the silk in place. Use a long piece of string to anchor the material in place. When it is holding the material around so it doesn’t move, tie the string.
Step 3 Add 3 tablespoons of vinegar to a pot of water and bring it to a boil. Place the eggs in the boiling water and keep them in the water (with at least a rolling boil) for 20 minutes.
Step 4 Take the wrapped eggs out of the pot and let them cool in open air with the material still on them. Once they are cool, remove the wrappings and you should have a beautifully-decorated egg.
Step 5 *Although my class did not do this, you can rub the eggs with vegetable oil to give them a shiny appearance.
The Science
I found out that silk is dyed using acid dyes. Having both heat and vinegar helps a chemical reaction take place that allows the colour from the silk to transfer to the eggs.
Materials: vinegar, 100% silk ties, cotton (t-shirt material works), string, a glass or enamel pot (I have used stainless steel and it worked too), vegetable oil*
Step 1 Cut up silk ties or silk scarves into pieces big enough to easily cover the surface of the eggs. Cut up the cotton into pieces also large enough to completely cover the eggs
Step 2 Wrap the silk around the egg so the egg is completely covered and so the darkest part of the silk is touching the egg shell. Now wrap the cotton tightly around the egg and silk to hold the silk in place. Use a long piece of string to anchor the material in place. When it is holding the material around so it doesn’t move, tie the string.
Step 3 Add 3 tablespoons of vinegar to a pot of water and bring it to a boil. Place the eggs in the boiling water and keep them in the water (with at least a rolling boil) for 20 minutes.
Step 4 Take the wrapped eggs out of the pot and let them cool in open air with the material still on them. Once they are cool, remove the wrappings and you should have a beautifully-decorated egg.
Step 5 *Although my class did not do this, you can rub the eggs with vegetable oil to give them a shiny appearance.
The Science
I found out that silk is dyed using acid dyes. Having both heat and vinegar helps a chemical reaction take place that allows the colour from the silk to transfer to the eggs.
Screaming Balloons? (video goodness included)
Screaming Balloons are easy to make. And they are not at all annoying to listen to for parents and siblings. Perhaps this is a great activity for when the in-laws come over and they are overstaying their visit.
Materials: a hex nut and a balloon
Caution
Parents with young children should make sure to blow the balloon up themselves so the child does not swallow the hex nut. Young children aren't great at blowing up balloons anyway, so this is a no brainer.
Step 1
Place the nut in the uninflated balloon.
Step 2
Inflate the balloon and tie it.
Step 3
Move the balloon around in circles until you get the nut spinning on its edge. This takes a little practice. Once the nut is spinning on its edge, you have awesome screaming sounds.
Step 4
Try this with different sized hex nuts or different sized balloons. What happened?
The Science
When the hex nut is spinning around, it is bouncing around the balloon causing vibrations. These vibrations produce the sound. (It's either that or the balloon trying to give you a message.)
Watch the video below to see the screaming balloon in action.
Oh and the credit goes to my wonderful apprentice Aaron Bannister for giving me this idea.
Materials: a hex nut and a balloon
Caution
Parents with young children should make sure to blow the balloon up themselves so the child does not swallow the hex nut. Young children aren't great at blowing up balloons anyway, so this is a no brainer.
Step 1
Place the nut in the uninflated balloon.
Step 2
Inflate the balloon and tie it.
Step 3
Move the balloon around in circles until you get the nut spinning on its edge. This takes a little practice. Once the nut is spinning on its edge, you have awesome screaming sounds.
Step 4
Try this with different sized hex nuts or different sized balloons. What happened?
The Science
When the hex nut is spinning around, it is bouncing around the balloon causing vibrations. These vibrations produce the sound. (It's either that or the balloon trying to give you a message.)
Watch the video below to see the screaming balloon in action.
Oh and the credit goes to my wonderful apprentice Aaron Bannister for giving me this idea.
A Classic - Rock Candy
This activity is not a new one, but it is very rewarding for the patient (and agonizing for all others). Anyway, who doesn't love candy or crystals?
Materials: water, clear plastic cups, a spoon, pencils, a one litre cup glass measuring cup, a kettle, a big bag of white sugar, food colour, cotton or wool string, paper clips, plastic wrap, and the patience of a kindergarten teacher
Warning: In case this isn't obvious, this activity needs to be done with adult supervision as it involves boiling water. Furthermore, if you use paper clips, make sure your children don't eat them when they eat the rock candy.
What to do:
Step 1
Boil 500 - 600 ml of water, pour it into the glass and dissolve as much sugar into it as is humanly possible. And then dissolve some more in.
Step 2
While the sugar water is cooling, tie strings to a pencil and trim them so they hang down just above the bottom of the cup. Attach paper clips so the string hangs down rather than stick to the side. Rub the bottom end of the string in some sugar so that it sticks to the string.
Step 3
Pour some cooled sugar water into the cups and add food colour because food colour makes everything better. Lower the strings into the cups. Place the cups in a warm room, if possible. Cover the cups so that dust does not collect, but be sure that the plastic wrap does not form an airtight seal. This is not necessary or helpful.
Step 4
Wait at least three weeks unless you live in Saudi Arabia. As you can see from my picture, most of the crystals did not form on the string (I actually forgot the step about rubbing sugar on to the bottom of the string). When crystals have formed, take them out and dry them.
Step 5
These are some things you could do with the sugar crystals:
1. Eat them
2. Make jewelry and fool your relatives into thinking you have come into an inheritance
3. Decorate fancy cakes with them
4. Try to pawn them at a jewelry shop (choose a less experienced jeweller)
5. Make a crown and order your family around imperiously
The Science:
By boiling the water, you made it easy to dissolve lots of sugar in. You may have dissolved as much as you could. When water is cooler, it is difficult to dissolve a lot of sugar in. By dissolving the maximum amount of sugar and then letting the water cool, you have made a super-saturated solution. Over time, the sugar molecules will bump into each other and sometimes they will stick to each other. The fact that the sugar molecules stick together in a pattern is what makes them crystals. Rubbing sugar on the bottom of the string adds seed crystals. Sugar molecules usually stick to the seed crystals and you have rock candy faster.
Materials: water, clear plastic cups, a spoon, pencils, a one litre cup glass measuring cup, a kettle, a big bag of white sugar, food colour, cotton or wool string, paper clips, plastic wrap, and the patience of a kindergarten teacher
Warning: In case this isn't obvious, this activity needs to be done with adult supervision as it involves boiling water. Furthermore, if you use paper clips, make sure your children don't eat them when they eat the rock candy.
What to do:
Step 1
Boil 500 - 600 ml of water, pour it into the glass and dissolve as much sugar into it as is humanly possible. And then dissolve some more in.
Step 2
While the sugar water is cooling, tie strings to a pencil and trim them so they hang down just above the bottom of the cup. Attach paper clips so the string hangs down rather than stick to the side. Rub the bottom end of the string in some sugar so that it sticks to the string.
Step 3
Pour some cooled sugar water into the cups and add food colour because food colour makes everything better. Lower the strings into the cups. Place the cups in a warm room, if possible. Cover the cups so that dust does not collect, but be sure that the plastic wrap does not form an airtight seal. This is not necessary or helpful.
Step 4
Wait at least three weeks unless you live in Saudi Arabia. As you can see from my picture, most of the crystals did not form on the string (I actually forgot the step about rubbing sugar on to the bottom of the string). When crystals have formed, take them out and dry them.
Step 5
These are some things you could do with the sugar crystals:
1. Eat them
2. Make jewelry and fool your relatives into thinking you have come into an inheritance
3. Decorate fancy cakes with them
4. Try to pawn them at a jewelry shop (choose a less experienced jeweller)
5. Make a crown and order your family around imperiously
The Science:
By boiling the water, you made it easy to dissolve lots of sugar in. You may have dissolved as much as you could. When water is cooler, it is difficult to dissolve a lot of sugar in. By dissolving the maximum amount of sugar and then letting the water cool, you have made a super-saturated solution. Over time, the sugar molecules will bump into each other and sometimes they will stick to each other. The fact that the sugar molecules stick together in a pattern is what makes them crystals. Rubbing sugar on the bottom of the string adds seed crystals. Sugar molecules usually stick to the seed crystals and you have rock candy faster.
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Mini Hovercraft
I'm a little miffed at the 21st century. TV phones (Skype and FaceTime) aren't as fun as I thought they'd be. And I still don't have a jet pack or a flying car. But at least I can make a (mini) hovercraft. That will have to do for now until I build a hovercraft I can ride.
Materials:
a balloon, a glue gun, a hacksaw, sandpaper, a two litre bottle, a plastic bag clip, and a CD (not one which reads "only backup of PhD thesis")
What to do:
Step 1 [With an adult]
Cut off the top of the two litre bottle just below the rim that sticks out. Sand the bottom at the cut so that it is flat. Glue the bottle top onto the middle of the CD (shiny side up looks nice).
Step 2
Once the glue has dried, inflate a balloon and use the bag clip to keep the air from escaping. Attach the balloon to the hovercraft by putting the mouth of the balloon over the bottle top. Be sure the balloon opening is centred.
Step 3
Place the balloon on a very flat surface such as a smooth table top or a marble counter top. Remove the clip and release the hovercraft.
Optional, but fun Step 4
Terrorize your mischievous kitten with yet another balloon experiment when she makes the mistake of trying to climb on the dinner table. (Note: kitten required)
The Science:
The balloon is made of latex which is stretched when inflated. The stretched balloon creates a higher pressure area inside the balloon as it tries to return to its non-stretched shape. The higher pressure pushes the air out through the hole in the CD. Due to the round shape of the CD, the air comes out more or less evenly. The cushion of air that comes out lifts up the hovercraft as it pushes down. When the sides are not touching the table, there is very little friction and the hovercraft moves quite freely.
Materials:
a balloon, a glue gun, a hacksaw, sandpaper, a two litre bottle, a plastic bag clip, and a CD (not one which reads "only backup of PhD thesis")
What to do:
Step 1 [With an adult]
Cut off the top of the two litre bottle just below the rim that sticks out. Sand the bottom at the cut so that it is flat. Glue the bottle top onto the middle of the CD (shiny side up looks nice).
Step 2
Once the glue has dried, inflate a balloon and use the bag clip to keep the air from escaping. Attach the balloon to the hovercraft by putting the mouth of the balloon over the bottle top. Be sure the balloon opening is centred.
Step 3
Place the balloon on a very flat surface such as a smooth table top or a marble counter top. Remove the clip and release the hovercraft.
Optional, but fun Step 4
Terrorize your mischievous kitten with yet another balloon experiment when she makes the mistake of trying to climb on the dinner table. (Note: kitten required)
The Science:
The balloon is made of latex which is stretched when inflated. The stretched balloon creates a higher pressure area inside the balloon as it tries to return to its non-stretched shape. The higher pressure pushes the air out through the hole in the CD. Due to the round shape of the CD, the air comes out more or less evenly. The cushion of air that comes out lifts up the hovercraft as it pushes down. When the sides are not touching the table, there is very little friction and the hovercraft moves quite freely.
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Hovering Ping Pong Ball
Materials: a ping pong ball, a hair dryer and a flexible straw
Step 1
Plug in the hair dryer. If the hair dryer has a cool setting, set it to that. Turn it on and point it straight up.
Step 2
Place the ping pong ball directly in the stream of air. Voila! It should stay up.
Step 3
Try the same thing by blowing through a flexible straw. Place the ball in the stream as before. (* I did not take a picture of this as it takes a lot of effort exhaling forcefully enough and it's tough to get a decent picture.)
The Science
The force of the air coming out of the hair dryer balances the force of gravity pulling the ping pong ball down. If the ball starts to fall out of the stream, the higher pressure outside the stream gives the ball a push back into the stream. A scientist named Bernoulli figured out that if there is faster moving air on one side, there will be less pressure on the other side. This is how a plane flies. The curved wing makes air travel faster on top and the higher air pressure below pushes the wing up.
Step 1
Plug in the hair dryer. If the hair dryer has a cool setting, set it to that. Turn it on and point it straight up.
Step 2
Place the ping pong ball directly in the stream of air. Voila! It should stay up.
Step 3
Try the same thing by blowing through a flexible straw. Place the ball in the stream as before. (* I did not take a picture of this as it takes a lot of effort exhaling forcefully enough and it's tough to get a decent picture.)
The Science
The force of the air coming out of the hair dryer balances the force of gravity pulling the ping pong ball down. If the ball starts to fall out of the stream, the higher pressure outside the stream gives the ball a push back into the stream. A scientist named Bernoulli figured out that if there is faster moving air on one side, there will be less pressure on the other side. This is how a plane flies. The curved wing makes air travel faster on top and the higher air pressure below pushes the wing up.
Trick People with the Cartesian Diver (By request)
Materials: candle, match, pen cap, plasticine, water, two litre bottle
Step 1
Light the candle and drip wax onto the top of the pen cap to block the hole. Make sure the hole is completely blocked.
Step 2
Make a small round ball of plasticine roughly the size pictured to the left. Attach it to the bottom of the pen cap arm.
Step 3
Fill a two litre bottle with no space for air and put the pen cap diver in. The diver should float. Put the lid on the bottle and squeeze the bottle. If the diver dives easily with a gentle squeeze and comes up quickly when you stop squeezing, your diver is ready. But you will probably have to experiment with the amount of plasticine to get the right amount. Keep adding or removing plasticine until it dives easily and rises as soon as you stop squeezing.
Step 4
Tell a group of kids or friends that the pen cap diver will dive if they clap their hands. If you time it right and squeeze so they don't notice, they may think that this statement is true. Give them the bottle and see if they can make it work (they likely will not know to squeeze). When that doesn't work, I tell them to move the bottle to the left (and squeeze while it is moving). Then I show them that if I move it to the right, the diver comes back up (I don't squeeze when moving to the right). I keep stringing them along as long as possible. I have convinced people they can make the diver dive by sticking their tongue out of the left side of their mouth.
The Science:
There is a small pocket of air inside the diver. When you squeeze the bottle, the air is compressed into a small space and water fills the diver. The diver then has less buoyancy and proceeds to dive. Releasing the pressure on the bottle immediately increases the size of the air pocket and it is more buoyant, rising once again.
Please note:
If the bottle is turned upside down or even on its side, the air may come out of the pen cap diver and the diver will sink. To fix it, remove the diver, drain the water and refill the bottle once again putting the diver in it.
Tell a group of kids or friends that the pen cap diver will dive if they clap their hands. If you time it right and squeeze so they don't notice, they may think that this statement is true. Give them the bottle and see if they can make it work (they likely will not know to squeeze). When that doesn't work, I tell them to move the bottle to the left (and squeeze while it is moving). Then I show them that if I move it to the right, the diver comes back up (I don't squeeze when moving to the right). I keep stringing them along as long as possible. I have convinced people they can make the diver dive by sticking their tongue out of the left side of their mouth.
The Science:
There is a small pocket of air inside the diver. When you squeeze the bottle, the air is compressed into a small space and water fills the diver. The diver then has less buoyancy and proceeds to dive. Releasing the pressure on the bottle immediately increases the size of the air pocket and it is more buoyant, rising once again.
Please note:
If the bottle is turned upside down or even on its side, the air may come out of the pen cap diver and the diver will sink. To fix it, remove the diver, drain the water and refill the bottle once again putting the diver in it.
Easy and Fun - Marshmallow Structures
Materials: mini marshmallows and toothpicks
Step 1
Show the kids that you can make things or structures by sticking the toothpicks into the marshmallows.
Just let the kids start making things without feeling a need to guide it too much.
Step 1
Show the kids that you can make things or structures by sticking the toothpicks into the marshmallows.
Just let the kids start making things without feeling a need to guide it too much.
Step 2
If you really are not satisfied with the kids making turtles or something artistic, you can challenge them to see how high of a structure they can make. They can also be challenged to make a bridge that will hold a certain amount of weight.
Step 3
Another challenge would be to have the kids build things out of squares and triangles and compare the structures to find out which are stronger.
Oh and good luck getting them to eat at the meal that follows this activity.
If you really are not satisfied with the kids making turtles or something artistic, you can challenge them to see how high of a structure they can make. They can also be challenged to make a bridge that will hold a certain amount of weight.
Step 3
Another challenge would be to have the kids build things out of squares and triangles and compare the structures to find out which are stronger.
Oh and good luck getting them to eat at the meal that follows this activity.
Electric Play Dough! Yes, you read that correctly.
Thanks to my apprentice Aaron for giving me the idea and Wired.com for providing the specifics, I present ELECTRIC PLAY DOUGH.
I should add that no children were harmed in the making of this blog post. Not this one, anyway.
I will paraphrase the directions from Wired.com. I should add that this activity is much more complicated than my usual suggestions to try at home, but for the science fan, this needs to be tried.
Materials: flour, water, distilled water, salt, cream of tartar, vegetable oil, sugar, alum, food colour, LED lights, alligator clips, a battery holder that takes at least 4 AA batteries (AAA, C, or D would work too), four AA batteries, bowls, a pot, measuring spoons, patience
Batch A - Play dough that conducts electricity (the conductor)
Mix together 1 ½ cups of flour, ¼ cup salt, 1 tbsp of vegetable oil, some food colour, 1 cup of water (tap water is fine), and 3 tbsp cream of tartar, in a medium size pot. Heat it at low or medium heat and keep stirring it until it is a ball in the middle of the pot. Carefully remove the VERY HOT dough and very carefully knead it with a bit more flour so it is not too sticky. Set aside.
Batch B - Play dough that does not conduct electricity (the insulator)
In a bowl, mix together 1 ½ cups of flour, ½ cup of sugar, 3 tbsp. of vegetable oil, ½ cup of distilled water, some food colour (a different colour than Batch A) and 1 tsp alum. Keep mixing it until it is like bread dough and it is not too sticky. Knead this batch adding flour until it is not too sticky.
Make the circuit
Attach alligator clips to the wires that come out of the battery holder. Put the batteries in the battery holder. Now make a circuit (see the pics). For the non-technical, just think of this as a circular path that the electrons can follow that is unbroken. Batch B (the insulator - yellow here) is play dough that will stop the electricity from flowing. Use the two ends of the LED to bypass Batch B. Keep in mind that electricity can only flow in one direction through an LED. If your circuit is not working, try to turn the LED the other way. Remember, if at first there is no electricity flowing, call an electrician. Just kidding. Keep experimenting with the circuit.
In case it is not clear (redundancy alert):
In the picture just below (on the right), you can see that the electricity is flowing because the LED is on. The yellow play dough is an insulator and does not let electricity pass through it. But the electricity bypasses the yellow play dough and goes through the LED light. The green and blue play dough conduct electricity.
The Science:
I am not going to get much more technical. The conductive play dough (Batch A) has ingredients that allow electrons to pass through it - salt for one. The insulating play dough (Batch B) does not allow electrons to pass through it - the sugar helps stop the electrons. A circuit is simply a path for electrons to follow. The LED releases some energy in the form of photons (light). Basically, your circuit is a circular path that has a spot in which photons are released. The play dough that conducts electricity acts as a wire.
WARNING: PLEASE DO NOT TRY TO REWIRE YOUR HOME WITH PLAY DOUGH! I AM NOT RESPONSIBLE FOR THE AFTERMATH OF THIS APPLICATION OF THE ACTIVITY.
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Strange Paper Airplane - The Hoop Glider
This is a simple and fun way to make a new kind of paper airplane. In fact, many people will insist it won't fly when they see it. All the more reason to make one. Prove your critics wrong!
Materials: a piece of paper or card stock, scissors, clear tape, a straw (avoid the flexible straws, if possible)
Step 1
Cut two pieces of paper, one longer than the other. I don't measure, but some people prefer to. Here are the measurements I used this time:
Short strip: 3 cm by 14 cm
Long Strip: 2.5 cm by 22 cm
Step 2
Fold the two strips into circles and tape them together.
Step 3
Tape the two strips onto the straw as pictured in the final photo below. Test out your plane!
*Step 4
Keep making these planes and compare different sizes to find out what is the most effective size of paper strips. Or add other accessories to the plane and see if you can improve its flight. Email me at glennfromx2@gmail.com if you have a successful new design.
The Science
The two hoops on each end help to keep the plane balanced. The big hoop creates drag (or friction with the air) and that helps to keep the straw level. The small hoop in front keeps the plane on a direct course. The air goes through the hoops as it flies.
By the way, this is one of the few science activities I've done that Felix the Reluctant Lab Cat actually approves of. Most of the rest have involved explosions, implosions, smoke, bright lights, noise, massive volumes of coloured foam, smelly chemicals or several of the above. Felix is not very dedicated to the study of science at this point in time.
Materials: a piece of paper or card stock, scissors, clear tape, a straw (avoid the flexible straws, if possible)
Step 1
Cut two pieces of paper, one longer than the other. I don't measure, but some people prefer to. Here are the measurements I used this time:
Short strip: 3 cm by 14 cm
Long Strip: 2.5 cm by 22 cm
Step 2
Fold the two strips into circles and tape them together.
Step 3
Tape the two strips onto the straw as pictured in the final photo below. Test out your plane!
*Step 4
Keep making these planes and compare different sizes to find out what is the most effective size of paper strips. Or add other accessories to the plane and see if you can improve its flight. Email me at glennfromx2@gmail.com if you have a successful new design.
The Science
The two hoops on each end help to keep the plane balanced. The big hoop creates drag (or friction with the air) and that helps to keep the straw level. The small hoop in front keeps the plane on a direct course. The air goes through the hoops as it flies.
By the way, this is one of the few science activities I've done that Felix the Reluctant Lab Cat actually approves of. Most of the rest have involved explosions, implosions, smoke, bright lights, noise, massive volumes of coloured foam, smelly chemicals or several of the above. Felix is not very dedicated to the study of science at this point in time.
Remove The Shell From An Egg
This activity takes time (24 hrs.), but it is interesting and a good opportunity for kids to make observations. The kids remove the shell from an egg using chemistry.
Materials: an egg, a clear glass jar or a plastic cup, white vinegar
Step 1
Discuss what the parts of an egg are. Maybe even break one open and examine its various parts. Ask the kids what they think an egg shell is made of.
Step 2
Put an egg in the jar and fill the jar with vinegar until the egg is covered. Ask the kids to make observations about what they see happening. The distortion of the egg's shape by the jar or cup may even be more interesting than the gentle chemical reaction.
Step 3
Leave overnight. If there still is a shell the next day, replace the old vinegar with newer vinegar. By the next day, you should have no shell.
If you are working in a place where you can make a mess, trying dropping the now shell-less egg. Does it bounce? If yes, how high can you drop it before it breaks? If no, you better clean that mess up.
The Science: The egg shell is made of a chemical called calcium carbonate (mostly). Vinegar is an acid and its hydrogen combines with oxygen to make water. The bubbles of gas are actually carbon dioxide (CO2). There is some calcium left over too. It is the white powder left on the egg or on the bottom of the jar.
Materials: an egg, a clear glass jar or a plastic cup, white vinegar
Step 1
Discuss what the parts of an egg are. Maybe even break one open and examine its various parts. Ask the kids what they think an egg shell is made of.
Step 2
Put an egg in the jar and fill the jar with vinegar until the egg is covered. Ask the kids to make observations about what they see happening. The distortion of the egg's shape by the jar or cup may even be more interesting than the gentle chemical reaction.
Step 3
Leave overnight. If there still is a shell the next day, replace the old vinegar with newer vinegar. By the next day, you should have no shell.
If you are working in a place where you can make a mess, trying dropping the now shell-less egg. Does it bounce? If yes, how high can you drop it before it breaks? If no, you better clean that mess up.
The Science: The egg shell is made of a chemical called calcium carbonate (mostly). Vinegar is an acid and its hydrogen combines with oxygen to make water. The bubbles of gas are actually carbon dioxide (CO2). There is some calcium left over too. It is the white powder left on the egg or on the bottom of the jar.
About an hour after I put the vinegar in, I noticed the egg was floating (good teachable moment potential here).
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An island of bubbles appeared at the top.
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The end result is an egg with no shell whatsoever. It is very bouncy, but I have no desire to find out exactly how bouncy. A vinegary, raw egg smell permeating my house is something I would rather just imagine. If you wish to try it, email me the results. I'd love to know how high it can bounce.
Cabbage Chemistry
The cups with the test foods behind them
Having boiled up 6 litres of purple cabbage water for a workshop and only having used up about 1 litre, this seems the perfect time to post about this activity. Hopefully Felix the Kitty won't try to interfere with the results.
This is a simple activity that looks like complex chemistry. It tests whether a material is an acid or a base and it does so with colour changes. If the food tested is an acid, it will turn the cabbage water pink. Bases turn it green or blue.
Materials: purple cabbage, water, knife, pot, stove, strainer, pitcher/big bottle, clear cups, spoons or stir sticks, ** vinegar, Alka-Seltzer, baking powder, hot sauce, baking soda, lime juice, egg, tomato sauce and many different kinds of foods if you wish (some will not have a conclusive colour change). **I put the foods that I used today in order from left to right.
Step 1
Chop up the purple cabbage and boil it in water until the water is a dark purple. Your home will stink, but you'll bear this burden in the name of science. Strain and keep the purple water. Allow it to cool (for safety).
Step 2
Pour a bunch of half-filled cups of purple water and choose different foods to try putting in (suggestions in the materials). They may need to stir some of them. Keep testing foods as long as you have materials.
Step 3
Keep track of which foods are acids and which are bases.
The Science:
Simply put, acids are things that taste sour and lose hydrogen ions. Bases feel slippery and gain hydrogen ions. Purple cabbage water is an indicator. Indicators tell us if something is an acid or a base.
This is a simple activity that looks like complex chemistry. It tests whether a material is an acid or a base and it does so with colour changes. If the food tested is an acid, it will turn the cabbage water pink. Bases turn it green or blue.
Materials: purple cabbage, water, knife, pot, stove, strainer, pitcher/big bottle, clear cups, spoons or stir sticks, ** vinegar, Alka-Seltzer, baking powder, hot sauce, baking soda, lime juice, egg, tomato sauce and many different kinds of foods if you wish (some will not have a conclusive colour change). **I put the foods that I used today in order from left to right.
Step 1
Chop up the purple cabbage and boil it in water until the water is a dark purple. Your home will stink, but you'll bear this burden in the name of science. Strain and keep the purple water. Allow it to cool (for safety).
Step 2
Pour a bunch of half-filled cups of purple water and choose different foods to try putting in (suggestions in the materials). They may need to stir some of them. Keep testing foods as long as you have materials.
Step 3
Keep track of which foods are acids and which are bases.
The Science:
Simply put, acids are things that taste sour and lose hydrogen ions. Bases feel slippery and gain hydrogen ions. Purple cabbage water is an indicator. Indicators tell us if something is an acid or a base.
Lime juice on the left and egg on the right
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Vinegar, Alka-Seltzer and baking powder
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The purple cabbage water indicates a variety of acids and bases.
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Elephant's Toothpaste (safe for kids/kittens version)
There are lots of dramatic videos on YouTube of "Elephant's Toothpaste." This is a safer version of that experiment. I do not recommend trying the more serious version unless you have a science/chemistry background.
Materials: a cup, yeast, warm water, a flask or bottle, 3% hydrogen peroxide, food colour and dish soap
Step 1
Put 125 ml. of warm water in a cup and add yeast. Set aside for ten minutes or until it has risen.
Step 2
Pour about 100 ml. of hydrogen peroxide into the flask or bottle. Add some food colour and dish soap. Swirl it around to mix it.
Step 3
Add the yeast mix to the coloured, soapy hydrogen peroxide and watch the oxygen come out of the peroxide and form bubbles.
**Note that my kitten, Felix, has momentarily gotten over her fear of my science experiments and began to test the foam in the third picture.
The science:
The yeast acts as a catalyst and helps the oxygen to come out of the peroxide. The soap helps make bubbles and so you have oxygen-filled soap bubbles for the foam.
Materials: a cup, yeast, warm water, a flask or bottle, 3% hydrogen peroxide, food colour and dish soap
Step 1
Put 125 ml. of warm water in a cup and add yeast. Set aside for ten minutes or until it has risen.
Step 2
Pour about 100 ml. of hydrogen peroxide into the flask or bottle. Add some food colour and dish soap. Swirl it around to mix it.
Step 3
Add the yeast mix to the coloured, soapy hydrogen peroxide and watch the oxygen come out of the peroxide and form bubbles.
**Note that my kitten, Felix, has momentarily gotten over her fear of my science experiments and began to test the foam in the third picture.
The science:
The yeast acts as a catalyst and helps the oxygen to come out of the peroxide. The soap helps make bubbles and so you have oxygen-filled soap bubbles for the foam.
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Exploding Colours!
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The title is a bit of a giveaway, but this is a fun experiment everyone should try.
Materials: homogenized milk, food colour, a plate, dish soap Step 1 Put just enough homogenized milk on a plate to cover it with milk. Step 2 Add a few drops of at least 3 colours of food colour to the milk. Do not stir this. Step 3 Put a drop of dish soap in the middle of one of the blobs of colour and then do the same to the other blobs of colour. Step 4 Observe the results. The Science: Soap is an emulsifier. One end of the soap molecule is hydrophobic which means "scared of water" which really means it does not stick to water. It sticks to fat molecules. The other end of the soap molecule is hydrophilic which means "loves water" which really means it sticks to water. So when you put the dish soap in the colours in the milk, the colour is spread out as the soap moves around sticking to the water and soap molecules. Rinse and repeat! |
Silly Putty Update
An activity I suggested a few weeks ago was Silly Putty (scroll down past the blacklight experiment). This is an update to that activity.
It turns out that the homemade white silly putty makes incredible prints. Use the recipe below, but don't add food colour. Then draw various things on ordinary paper with watercolour felts. Spread out the white silly putty to cover the whole image and wait about five minutes. Peel it off and PRESTO, you have a silly putty print.
It turns out that the homemade white silly putty makes incredible prints. Use the recipe below, but don't add food colour. Then draw various things on ordinary paper with watercolour felts. Spread out the white silly putty to cover the whole image and wait about five minutes. Peel it off and PRESTO, you have a silly putty print.
Write backwards or you'll have cryptic speech bubbles! (unless that is the plan)
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Extract Banana or Onion DNA - It's Easy
It sounds complicated, but the process is surprisingly easy. But don't be expecting to see the double helix as we are used to seeing in books. The DNA will look like the white stuff in the picture on the left.
Materials: banana or onion, knife, blender, dish soap, salt, rubbing alcohol, toothpicks, strainer, glass jar, warm water
Step 1
Put the rubbing alcohol in the freezer. It needs to be very cold.
Step 2
Cut up the banana or onion into small pieces and put those in the blender with 5ml. of salt and enough warm water to cover the mix. Blenderize on the lowest setting for 5 - 10 seconds.
Step 3
Pour the mix through a strainer and keep the filtrate - the liquidy part of the mix (you need the jar about half full).
Step 4
Pour 10 ml. of dish soap into the jar and gently stir. Do not stir hard enough to make bubbles. Now pour the cold rubbing alcohol into the mix, but pour it slowly allowing it to hit the side of the jar as you pour it in. Keep filling the jar until it is close to being full. The point is to create two separate layers, so pour slowly. Now let this sit for five minutes.
Step 5
Come back five minutes later and use a toothpick to remove the strands of DNA. Twist the toothpick to pick up the strands.
Congratulations! You have extracted DNA. If that doesn't make you feel like a scientist, I don't know what will. Maybe try building a spaceship, perhaps that would work. But I digress.
By the way, I read that this also works with chicken liver, but I have not tried this. Please try it and email me to tell me how it worked.
The Science:
I'll admit, I am kind of out of my league on this own (not unusual). But I did some research and found out a few things about this process. The salt helps the DNA to stay together during the blenderizing part of the process. The soap breaks down the cell membrane by dissolving the fatty molecules and proteins of the cell and breaking the bonds that hold the cell membrane together. DNA is not soluble in alcohol so the DNA precipitates or comes out of the solution.
Another Fun Idea:
You can make DNA using candy! What better combination is there than science and candy? Check out this link to find out how.
Materials: banana or onion, knife, blender, dish soap, salt, rubbing alcohol, toothpicks, strainer, glass jar, warm water
Step 1
Put the rubbing alcohol in the freezer. It needs to be very cold.
Step 2
Cut up the banana or onion into small pieces and put those in the blender with 5ml. of salt and enough warm water to cover the mix. Blenderize on the lowest setting for 5 - 10 seconds.
Step 3
Pour the mix through a strainer and keep the filtrate - the liquidy part of the mix (you need the jar about half full).
Step 4
Pour 10 ml. of dish soap into the jar and gently stir. Do not stir hard enough to make bubbles. Now pour the cold rubbing alcohol into the mix, but pour it slowly allowing it to hit the side of the jar as you pour it in. Keep filling the jar until it is close to being full. The point is to create two separate layers, so pour slowly. Now let this sit for five minutes.
Step 5
Come back five minutes later and use a toothpick to remove the strands of DNA. Twist the toothpick to pick up the strands.
Congratulations! You have extracted DNA. If that doesn't make you feel like a scientist, I don't know what will. Maybe try building a spaceship, perhaps that would work. But I digress.
By the way, I read that this also works with chicken liver, but I have not tried this. Please try it and email me to tell me how it worked.
The Science:
I'll admit, I am kind of out of my league on this own (not unusual). But I did some research and found out a few things about this process. The salt helps the DNA to stay together during the blenderizing part of the process. The soap breaks down the cell membrane by dissolving the fatty molecules and proteins of the cell and breaking the bonds that hold the cell membrane together. DNA is not soluble in alcohol so the DNA precipitates or comes out of the solution.
Another Fun Idea:
You can make DNA using candy! What better combination is there than science and candy? Check out this link to find out how.
Get a Blacklight and Experience Cool Glowing Stuff
If you can get your hands on a black light (Seeing is Believing sells them in Victoria), you can try out different things that glow.
Materials needed: a black light, highlighters, a hammer, clear glasses or jars, tonic water, water, glow in the dark bubbles (some toy stores now sell them), a UV pen (science supply companies have them - sometimes toy stores)
Step 1
Smash some NEON highlighters (not ordinary felts) with a hammer and remove the felt containing the ink. once removed, I sometimes cut the outside of the felt to allow the colour to come out better. Put the felt into a clear jar or glass with water. You will shortly have some brightly coloured water. Do this for several colours. Neon colours work the best.
Step 2
Get another clear jar and pour tonic water into the jar.
Step 3
Place the jars in front of a black light in a totally dark room and turn on the black light. Voila - cool glowing stuff!
Step 4
If you managed to find glow in the dark bubbles, blow bubbles near the black light while the room is darkened and the bubbles should have an eery, but beautiful glow.
Another Fun Black Light Activity - Scavenger Hunt
Find a UV pen and write on various surfaces of a room that can be darkened (walls and furniture work, but the marks may be visible later in direct sunlight). You can use the UV pen and the black light to create an interesting scavenger hunt in the dark. This works best if you find a portable black light that uses batteries so you can walk around with it.
The science: Black lights make UV light, a kind of light that is not in the visible spectrum for humans (we can't see it). Neon highlighters are bright because they absorb UV light and release it as visible light. The same goes for the glow in the dark bubbles. The black light provides extra UV light for them to change to visible light. Tonic water has quinine in it and quinine absorbs UV light and releases it as visible light too.
Materials needed: a black light, highlighters, a hammer, clear glasses or jars, tonic water, water, glow in the dark bubbles (some toy stores now sell them), a UV pen (science supply companies have them - sometimes toy stores)
Step 1
Smash some NEON highlighters (not ordinary felts) with a hammer and remove the felt containing the ink. once removed, I sometimes cut the outside of the felt to allow the colour to come out better. Put the felt into a clear jar or glass with water. You will shortly have some brightly coloured water. Do this for several colours. Neon colours work the best.
Step 2
Get another clear jar and pour tonic water into the jar.
Step 3
Place the jars in front of a black light in a totally dark room and turn on the black light. Voila - cool glowing stuff!
Step 4
If you managed to find glow in the dark bubbles, blow bubbles near the black light while the room is darkened and the bubbles should have an eery, but beautiful glow.
Another Fun Black Light Activity - Scavenger Hunt
Find a UV pen and write on various surfaces of a room that can be darkened (walls and furniture work, but the marks may be visible later in direct sunlight). You can use the UV pen and the black light to create an interesting scavenger hunt in the dark. This works best if you find a portable black light that uses batteries so you can walk around with it.
The science: Black lights make UV light, a kind of light that is not in the visible spectrum for humans (we can't see it). Neon highlighters are bright because they absorb UV light and release it as visible light. The same goes for the glow in the dark bubbles. The black light provides extra UV light for them to change to visible light. Tonic water has quinine in it and quinine absorbs UV light and releases it as visible light too.
Silly Putty (pictured in the header)
Silly Putty (or something very close to it) is actually rather easy to make. And yes, the first time, follow the recipe to the letter. Later you can start to experiment.
Materials needed: borax powder, Elmer's White Glue*, food colour, boiling water, cold water, a ziploc bag, a container or two
(* some glues don't work, use Elmer's to be sure it works)
Step 1
Mix 10ml of borax powder into 250ml of boiling water and set aside. This is called borax solution.
Step 2
Put 30 ml of Elmer's White Glue in a container. Add a few drops of food colour. add 20 ml of cold water. Stir until this gooey mixture is thoroughly mixed.
Step 3
Add 20 ml of borax solution to the glue/colour mix and stir for a few minutes. If you see pockets of white glue, pop them and keep mixing. When it seems as well mixed as stirring will get it, take out the gooey, stringy stuff and knead it in your hands until it has a consistent texture. Make sure there are no pockets of glue. If it still seems to be sticky from glue, pour a little borax solution on the outside of it and knead it again. You now have silly putty.
Keep it in a closed ziploc bag when you are not using it.
Experiment with it. Does it bounce? Does it stretch? Can you break it? What else can you do with it? Email me and tell me how it turned out.
The science: It is worth mentioning that the molecules in the glue are a polymer (they are long chains). When the borax solution is added, those chains get linked together in different places. That's what gives this silly putty its strange characteristics.
Materials needed: borax powder, Elmer's White Glue*, food colour, boiling water, cold water, a ziploc bag, a container or two
(* some glues don't work, use Elmer's to be sure it works)
Step 1
Mix 10ml of borax powder into 250ml of boiling water and set aside. This is called borax solution.
Step 2
Put 30 ml of Elmer's White Glue in a container. Add a few drops of food colour. add 20 ml of cold water. Stir until this gooey mixture is thoroughly mixed.
Step 3
Add 20 ml of borax solution to the glue/colour mix and stir for a few minutes. If you see pockets of white glue, pop them and keep mixing. When it seems as well mixed as stirring will get it, take out the gooey, stringy stuff and knead it in your hands until it has a consistent texture. Make sure there are no pockets of glue. If it still seems to be sticky from glue, pour a little borax solution on the outside of it and knead it again. You now have silly putty.
Keep it in a closed ziploc bag when you are not using it.
Experiment with it. Does it bounce? Does it stretch? Can you break it? What else can you do with it? Email me and tell me how it turned out.
The science: It is worth mentioning that the molecules in the glue are a polymer (they are long chains). When the borax solution is added, those chains get linked together in different places. That's what gives this silly putty its strange characteristics.
Amazing Bubble Art
Although I have taught kids to use bubbles to make Bubble Art for years, I recently discovered you can do much more if you play around with the project.
Materials needed: Miracle Bubbles (or some other commercial bubble mix), food colour, a straw, plastic container, paper, patience
Mix 5 ml or so of food colour with a small amount of bubble mix in a shallow container. Make two or three different colours of bubble mix this way. Get a spot on a table wet and wet the straw. Use the straw to blow a bubble onto the wet surface of the table. Just make one bubble and put the straw into different colours of soap mix. Touch the straw to the top of the bubble to make patterns on the bubbles. Take a piece of paper and slowly lower the paper onto the bubble. Sometimes it just pops, but there will be times when it leaves a spectacular image of a bubble.
Materials needed: Miracle Bubbles (or some other commercial bubble mix), food colour, a straw, plastic container, paper, patience
Mix 5 ml or so of food colour with a small amount of bubble mix in a shallow container. Make two or three different colours of bubble mix this way. Get a spot on a table wet and wet the straw. Use the straw to blow a bubble onto the wet surface of the table. Just make one bubble and put the straw into different colours of soap mix. Touch the straw to the top of the bubble to make patterns on the bubbles. Take a piece of paper and slowly lower the paper onto the bubble. Sometimes it just pops, but there will be times when it leaves a spectacular image of a bubble.
The complexity of the bubble prints you get can be quite surprising. Play around with it.
The science: I'm not sure. I don't think it matters that much. Just have fun with it.
The science: I'm not sure. I don't think it matters that much. Just have fun with it.
Another way to do it is to blow bubbles into the container and have them overflow. Touch the paper to a big bunch of bubbles and you get patterns like this:
Try the different containers and keep adding colours to the print.
One thing to avoid is foam. Foam is really small bubbles, but too much foam will not result in bubble prints so much as big globs of colour that do not resemble bubbles.
Try the different containers and keep adding colours to the print.
One thing to avoid is foam. Foam is really small bubbles, but too much foam will not result in bubble prints so much as big globs of colour that do not resemble bubbles.
Dish Soap-Powered Boat
Materials needed: an empty cereal box, scissors, dish soap, a tub with water
This idea is very easy. You take an empty cereal box and cut out boats in the shape pictured to the right. Then you put a tiny spot of dish soap right on the boat just at the top of the cut out square. But the spot of dish soap should be on the edge so that the soap touches the water when the boat is put in.
The science: As the soap spreads out in the water to bond with the water molecules, it gives the boat a little push. This can only be done once in a tub of water so you probably need to keep changing the water after every try. The boats also curl up from absorbing water.
This idea is very easy. You take an empty cereal box and cut out boats in the shape pictured to the right. Then you put a tiny spot of dish soap right on the boat just at the top of the cut out square. But the spot of dish soap should be on the edge so that the soap touches the water when the boat is put in.
The science: As the soap spreads out in the water to bond with the water molecules, it gives the boat a little push. This can only be done once in a tub of water so you probably need to keep changing the water after every try. The boats also curl up from absorbing water.
