(Do this outside) This is also known as a Mentos Eruption, Soda Geyser or just Diet Coke and Mentos.
DIET COKE & MENTOS ERUPTION (K- A tested)
This is a reaction between Mentos candy and cola. The experiment involves dropping several Mentos candies (usually 5–8) into a bottle of diet cola resulting in an eruption occurring because of rapidly expanding carbon dioxide bubbles on the surface of the Mentos.
I recently tried this experiment with three of my grandsons (Ages 6, 8,11; See photo) They all loved it! We quickly put the mentos into the Coke. The reaction starts immediately-so be quick!
If you want an explanation:
There are various theories being debated as to the exact scientific explanation of the phenomenon, many scientists claim that it is a physical reaction and not a chemical one. Water molecules strongly attract each other, linking together to form a tight connection around each bubble of carbon dioxide gas in the soda. To form a new bubble, water molecules must push away from one another. It takes extra energy to break this surface tension. So, in other words, water resists the expansion of bubbles in the soda.
When Mentos are dropped into soda, the gellan gum and gum arabic of the candy dissolves and breaks the surface tension. This disturbs the water connection, so that it takes less work to expand and form new bubbles. Each Mentos candy has thousands of tiny pores over its surface. These tiny pores function as nucleation sites, perfect places for carbon dioxide bubbles to form. As soon as the Mentos enter the soda, bubbles form all over their surface. They quickly sink to the bottom, causing carbon dioxide to be released by the carbonated liquid with which they come into contact along the way. The sudden increase in pressure pushes all of the liquid up and out of the bottle.
....is a model rocket fashioned from a 35mm film canister and propelled by the generation of gas from an effervescent liquid. It is often used in science classes to demonstrate principles of chemistry and physics to students.
1. In the experiment, a film canister is filled with water and an effervescent tablet (commonly Alka-Seltzer) and tightly sealed.
2. After a short time, the evolved carbon dioxide reaches sufficient pressure to cause the body of the canister to be launched into the air with a popping sound.
3. The canister may be elaborated with paper fins to resemble more closely af real rocket.
(K-A tested) MORE SIMPLE ROCKET LAUNCH... Fill a small plastic film canister (Fuji works well) with one teaspoon of water. Quickly add one Alka-Seltzer tablet, put the lid on and place the canister on the floor with the lid side down. Wait about 10 seconds and whoosh! Your rocket should fly into the air.
Lessons based around the Alka-Seltzer rocket can focus on a number of principles...
For example, the students are sometimes asked to experiment with the amounts of water and Alka-Seltzer to find the combination which propels the rocket the greatest distance.
Alternatively they may derive equations to calculate the speed and velocity of the rocket from the distance it travels.
If budget can afford it...purchase a life sized, plastic replica of a human skeleton. The children will be able to investigate how the bones are shaped, how the sizes related to each other and how the joints are restricted or facilitate movement. Children will clearly see how their own bones work. The cost would be about $50 but will be used for many years!....
(I'm known for my wackiness! Play the song Dem Bones-Barb)
An inexpensive and easily found alternative for hands-on skeleton activities can be found at the supermarket. Bones from turkeys', chickens' and pigs' feet can be cleaned and given to the children to reassemble.
Idea from: findarticles.com
- Materials: Black construction paper (approximately 6" x 11.5")
- Glue that will dry clear
- Lima beans (head, thorax, hips)
- Short, small macaroni in a tube (spine)
- Thin twisted macaroni (arms, legs)
- Elbow noodles (ribs)
- Small shells (joints)
- Spaghetti (fingers, toes)
- Black permanent marker
1. Build a sample skeleton for the children to copy from. Review the key features with them. 2. Guide children to build their skeleton working from the head down (i.e., head, neck/trunk, ribs, etc.), gluing the macaroni and beans to the paper as they go.
3. When they glue and macaroni has set, have them draw a smile and eyes on the "head".
As preparation for this project, study the human skeleton. Talk about symmetry between the two sides of the body, and how many ribs, fingers and toes we have. Source: Kaboose.com
WET DIAPER SCIENCE
What you Need: Diapers, resealable plastic bags, clear plastic cups, plastic teaspoons, water, blue food coloring
What to Do:
Show students a diaper. Once the giggles subside, ask them to guess how much water they think the diaper can hold, and record their responses.
- Invite small groups to cut out the waist and leg bands of a diaper and place the remainder in a bag.
- Separate the layers of the diaper and seal the bag.
- Shake the bag for two minutes. Kids will see a dry powder resting at the bottom. Have them remove everything from the bag except for this powder.
- Pour the powder (sodium polyacrylate) into a cup.
- Ask students to pour four ounces of water into a separate cup and add four drops of blue food coloring.
- Slowly spoon water into the cup with the powder, keeping track of the amount as you go.
How does the powder change? (It should now be a gel.)
Challenge students to predict how much more water this gel can hold.
- Continue to add spoonfuls of water, keeping track of the amount of water added and recording observations along the way, until the water no longer soaks into the gel. Ask students to determine how much water the powder can hold.
WHAT'S GOING ON: Sodium polyacrylate is a super-absorbent polymer that absorbs up to 300 times its weight in water. It is used in baby diapers to keep wetness away from a baby's skin. This polymer is also used as a soil substitute.
'MOO GOO' (K-A tested; image by K-A)
Ingredients: 1 cup whole milk, 2 Tablespoons white vinegar, Stove top or hot plate, small pot and strainer
Warm the milk in a pan, but do not boil. Remove the pan from the heat and SLOWLY stir in the vinegar. (The first time we made this, my grandson put the vinegar in at one time (it did not work)--when repeated and drizzled in slowly--it came together quickly. Barb)
- Continue to stir until a white rubbery substance forms in the liquid.
- Strain the liquid from the rubbery substance. If you've done the above diaper experiment, kids may correctly guess that they have created a polymer.
- Divide the polymer among youth and ask them to gently pat and roll it to remove any remaining liquid. (With this recipe there is only enough for one or two balls)
Test its physical properties. Kids will discover it stretches, bounces, and sticks to a surface.
WHAT'S GOING ON: This is a very nasty-tasting, yet edible, experiment. Cow's milk is loaded with the polymer casein, a protein. Without this polymer, cheese would come unglued. The casein is suspended in milk, but the vinegar causes cross-linking of the casein chains, resulting in visible clumping of the polymer. Casein is used in some glue. Without casein, glue would come unglued too.
EGG DROP (K-A tested-the grade school and middle school kids loved it!)
Each student works within guidelines to fashion a container for an egg so that the egg won't break when the student drops it from an established height…
Use hard boiled eggs (you could probably do raw-but be cautious of Salmonella and spoilage!).
Have each child create their own container for the egg -- with the purpose of the egg not breaking. Some kids have used "parachutes," and cans with foam. It can be a lot of fun!
Of course, everyone's hypothesis should be that their egg won't break.
The testing is the fun part---when the kids see if their egg remains intact! For this you want to drop the egg container from the highest available point.... A second floor balcony, off the top bleacher of the football field or by a teacher on a ladder?
*Even though this is for older students, it can be adapted to the lower grades without going into weight and velocity.
Materials you will need:
1. Draw a simple shape like a star or heart.
2. Place the mirror upright behind your drawing so that you can see it in the mirror.
3. Try drawing over your shape while looking into the mirror (keeping your eyes on the mirror all the time and not your paper).
When looking in the mirror, the top of your picture becomes the bottom. This makes it very difficult to copy your drawing (especially when the lines change direction).
2 tablespoons of pure lemon juice and cotton swabs
- Pour the lemon juice into a small dish.
- Soak the end of a cotton swab in the lemon juice and use it to write a secret message or a picture.
- To read or see your secret message, hold the paper near a warm light bulb, burner, or toaster.
- The heat will turn the invisible writing brown and you can see it!
WHIRLY GIG SPINNER--HOW LONG CAN YOU SPIN?
Film canister lid
1. Cut a circle out of construction paper, about the size of a DVD or CD.
2. Tape a film canister lid to the center of the paper circle. (You can draw a design on it-that would look interesting spinning)
3. With an adult- poke or drill a hole through the film canister lid.
4. Poke the skewer through the hole in the lid.
5. Keep the paper circle near the point of the skewer. Give the skewer a twirl.
HOW DOES IT WORK?
The paper circle gives the skewer extra mass. When you twirl the skewer, you also twirl all the mass of the paper circle. A spinning mass tends to keep spinning unless something like friction slows it down.
About 72% of kids can make it spin MORE than 10 seconds...
You will need an empty soda bottle and deflated balloon.
1. Show an empty soda bottle to the group & announce that although the bottle may look empty, you can prove that it's actually full.
2. Put a deflated balloon into the bottle---stretching the open end of the balloon over the mouth of the bottle.
3. Can your friend blow up the balloon while it's inside the bottle?? NO WAY!
4. WHY? No matter how hard you blow, you will not be able to blow up the balloon while it is inside the bottle. This is because the bottle is already completely full--of air. Even though it's invisible, air takes up space.
DOLLAR PICK UP TRICK
Even George Washington couldn't do this dollar pick-up trick! Tell the children you'll give them each a dollar if they can pick it up from the floor. But there is a catch: They have to pick it up using your instructions. You'll have fun fooling them with this easy indoor game for kids.
You'll need a dollar bill and a wall…
Step 1: Have children stand with their feet together and heels up against a wall.
Step 2: Put dollar bills on the floor 12 inches in front of their feet.
Step 3: Tell them to pick up the dollars without bending their knees or moving their feet.
It is impossible to do! Why? When you are standing against a wall, your center of gravity is over your feet. If you bend forward, you have to move your center of gravity forward to keep your balance. Since you can't move your feet during this trick, you're flat out of luck. But that's better than being flat on your face!
3 feet of String/Thread
1. Take the string and tie the fork to the centre of the string/thread.
2. Take one end of the string/thread and tie it around your right index finger (pointer), then tie the other end of the string/thread around your left index (pointer) finger.
3. Place your fingers (index/pointer) to your ears and let the fork dangle in front of you.
4. Get someone to tap the fork with the spoon. You should hear loud ringing in your ears.
The ringing sound travels up the string/thread to your ears.
You could tie other metal objects to the string/thread to see what sounds travel to your ears.
MUMMIFICATION PROCESS... Discover how the Ancient Egyptians used drying as one step…
#1 EXPERIMENT: FISH MUMMY
l raw fish from the market
Two boxes of baking soda
Plastic container with a lid
1. Weigh the fish on a kitchen scale.
2. Coat the fish inside and out with baking soda, and bury it completely in baking soda in the plastic container. Let it sit this way for a week in a cool shady place (in a refrigerator, if you like).
3. After a week, take it out, dust it off, and weigh it again. Re-bury it in fresh baking soda, for another whole week.
4. Take it out and weigh it once more.
What does the fish look, feel, and smell like?
HOW’S IT WORK?
Baking soda acts as a preservative and drying agent. The weight loss you noticed is due to the removal of water by the baking soda. Drying the fish is essential to making it a mummy. What happened after the first week? After the second week?
Notes from a boy who did it…Jordan, 6th Grade, NY
I tried the experiment called "Fish Mummy" On the first week when I took the fish out; the first thing I noticed was the smell. It smelled like the most disgusting thing you can think of. I described it as rotting eggs. The next thing I noticed was what it felt like. It was kind of stiff. I thought that it would have felt like Jell-O. On the second week that I took the fish out the smell wasn't as strong as usual. It didn't smell as bad.
Adapted from: pbskids.org
PROJECT #2: MUMMIFIED APPLE
1 Popsicle or craft stick
1 medium-sized plastic bags that seals
Natron Solution: 1/4 cup table salt, 1/2 cup sodium carbonate (powder bleach), and 1/2 cup baking soda; Stir together--this makes enough to do one apple. You may maximize this recipe as necessary.
TO DO AND OBSERVE
- Make the Natron solution (recipe above) in the plastic bag.
- Carve a face into the apple with the Popsicle stick then stick the Popsicle stick into the apple so you have a handle (like you were making a candy apple).
- Dip the apple into the Natron Solution until the face is covered, and leave the apple in the bag.
- Safety precautions: Do NOT eat the apple or the Natron Solution; wash your hands after the activity and don't touch your eyes or mouth until you wash your hands. You might want to wear plastic safety goggles. Leave the bag open in an upright position to allow air to flow.
Record your observations as your apple mummifies. What happens to the apple once it is covered with the Natron Solution? How much time does it take for the apple to turn into a "mummy"? (The mummification of the apple may take up to two weeks. Source: tryscience.org
SINK OR FLOAT...
CAN YOU SINK AN ORANGE?
You will need: A Bowl, Water, and an Orange
1. Fill the bowl with water.
2. Put in the orange...What happens to the orange? See if you can get the orange to sink.
3. Take the orange and peel it.
4. Place the peeled orange back in the bowl of water. What happens this time?
5. The orange sinks because the orange peel if full of trapped air pockets, therefore making the orange light for its size (so it floats).
6. When you remove the peel (including the air pockets) the orange weighs a lot for it.
Along with the above experiment try a ‘Sink or Float with a Pumpkin or Watermelon!
- Fill a bin or aquarium or tub half full with water. Place everyday items near the bin. Get the kids to guess which items would sink and which ones would float. Have youth write their guesses in their notebooks. Then do the experiments to determine if they were right or not.
- Be sure to add a watermelon to the guess! (You can eat it afterwards!) Pumpkins are also fun. The pumpkin and watermelon will float because its mass is less than the mass of water it displaces. This is due primarily because the inside of the pumpkin and melon are hollow. It is mostly air, which has a much lower mass than water.
CATCH AN ICE CUBE
Need: Ice cubes, cup of water, string, salt
1. Float an ice cube in the cup of water.
2. Carefully lay one end of a piece of string on the floating cube.
3. Sprinkle a pinch of salt onto the string and wait for about 30 seconds.
4. Pick up the string, and WOW, you caught an ice cube
5. But what else can you use besides salt? Try sugar, pepper, sand, flour, you name it. See what works, and what doesn't, and try to figure out why!
How's it work?
Salt that dissolves on the ice cube lowers its freezing point, which means that it actually melts faster than normal in the cup. After some of the salt washes away, a little bit of the water on the cube re-freezes, trapping the string with it. Substances that dissolve in water can lower the freezing point of ice, while things that don't dissolve can't.
From Jacy, age 12, MN (Catch an Ice Cube)
First I collected the materials that were needed. When I started with the salt and ice, I found that the salt melts the ice and then it refroze over the string. You could then lift up the string and the ice cube would be hanging from it. I tried doing this experiment with other substances like sugar, pepper, baking soda, and baking powder. I found that none of them worked like salt did to make the string stick to the ice cube. The experiment was cool.
Adapted from: pbskids.org
THREE CHRYSTAL EXPERIMENTS
#1 CHRYSTAL SHAPES
NEED: Epsom salt, a tablespoon, a cup of water, a paper circle, a jar lid
1. Cut out a paper circle the same size as the jar lid. Put the circle in the lid.
2. Measure 4 big tablespoons of Epsom salt. Don't worry if you add too much - the more, the better.
3. Dissolve all 4 tablespoons in the water and stir the mixture thoroughly.
4. Pour the water mixture into the jar lid. Stick the lid in a place where it won't be disturbed. It will take a few days, but let the water evaporate and see what happens!
HOW’S IT WORK?
In a few days, the water will evaporate from the lid. But the Epsom salt will be left behind. The salt will build up into its own unique crystal shape. You can make a miniature rock forest.
#2 CHRYSTAL GARDEN
Materials: Water, Alum (found in the spice section of supermarkets or drugstore), Clear glass bowl, Clean rocks and pebbles
1. Bring 1/2 cup of water to a boil.
2. Add 2 ounces of alum, stirring until the alum is dissolved.
3. Pour the solution into a clear glass bowl half filled with assorted clean rocks and pebbles.
4. Within hours you should be able to see alum crystals forming as glass-like squares. Within several days you should have a number of crystals to look at.
#3 CRYSTAL SNOWFLAKES
1. Cut a white pipe cleaner into 3 equal sections and twist it together to make a six-sided flake.
2. Tie a string from point to point to form the pattern.
3. Also, tie a piece to the top of one of the pipe cleaners and tie the other end to a pencil (This is for the snowflake to hang from)
4. Fill a wide mouth jar, cup or glass with boiling water.
5. Mix in Borax one tablespoon at a time (3 Tablespoons per cup of water) and stir it until it’s dissolved. (It’s alright if there is some settling.)
6. If desired, add a little blue food coloring at this point to tint the snow flake.
Totally immerse the snowflake in your solution. Rest the pencil on the top of the container letting the flake suspend freely in the solution. Wait overnight and the next day the children will have a snowflake covered with tiny crystals.
CRAFTY Science...This one is fun!!!! (Image by KidActivities.net)
TOOTHPICK TOWERS...Made using Cheese Puffs, Tootsie Rolls, Tooth Picks and Gummy Bears
1. Prepare large Ziploc bags with kids' names written on them.
2. Put small Ziploc bags inside the large ones.
3. Fill one small bag with about 100 toothpicks, another one with Tootsie Rolls, another one with Cheese Puffs, and the last one with Gummy Bears.
4. The kids' task is to BUILD THE TALLEST, MOST STABLE STRUCTURE, using the materials provided. (The structure in the image is 19"...the kids (my grandchildren 9 and 12 also decided to use a few mini-marshmallows.)
You can have the kids make structures that resemble molecule shapes using the same materials. The activity then becomes "Make a Molecule Center." NOTE: I saw my image of this activity posted awhile back on Pinterest. The description said it "...was made with sausages!" No, no, no... Lol! (Barb)
MAKE PAPER FROM TOILET PAPER!
Toilet paper (use an inexpensive brand – the coarser the better)
Empty plastic water bottle
Large dry sponge
Food coloring (optional)
1. First of all, make sure you have plenty of working space for this activity. Cover a table with newspaper to limit the mess.
2. Place 10 squares of toilet paper in the water bottle. Fill the bottle half full with water and close securely. If desired, you can add a few drops of food coloring to the bottle to create colored paper.
3. Have children count to 100 as they shake the bottle. This shaking will allow the toilet paper and water to make pulp.
4. Once the mixture looks like “slush”, the pulp is ready. Pour the pulp into the strainer in a thin, flat layer. Squeeze as much excess water out of the pulp as you can.
5. Prepare a working space with layers of newspaper to absorb the water. Without moving the layer of pulp with your hands, flip the strainer and let the pulp fall onto the layer of newspaper. Cover the pulp with a piece of waxed paper and use the rolling pin to squeeze out any excess water. Remove the waxed paper and place the sponge on the paper to absorb the excess water. You may have to repeat this process several times.
6. Once you’ve removed all of the excess water, allow the paper to dry overnight. The children now have their own piece of handmade paper. They can decorate the paper the next day, use it to write a note, or make a gift tag or pin. Be creative!
TRY MAKING... AN ERUPTING VOLCANO...
Note: K-A made version #1 with grandsons 'N' and 'B'. Although the boys thought the experiement very cool, we would make the 'mountain' itself differently next time. The 'dough' material didn't want to easily stay on the bottle. After adding more salt, water and oil--we were able to make a mountain of sorts. Repeating this activity, we would use a different play dough or modeling clay.
To the delight of the boys (ages 8 and 12), the volcano erupted for quite awhile. K-A has also successfully made volcanoes with the other methods.
Additional Note: 'N' thought it would also be cool to add adventure seeking climbers to the mountain. Hence, the 'dark blobs'--aka gummy bears-- on the face and bottom of the hill! Barb
#1 Version VINEGER VOLCANO
This is a classic science experiment, and an easy one. To make the volcano, mix 6 cups flour, 2 cups salt, 4 tablespoons cooking oil, and 2 cups of water. The mixture should be smooth and firm.
Stand a large soda bottle in a baking pan or shallow dish, and begin to shape the dough around it. Don't cover the hole and don't drop any of the dough into it. Fill the bottle about three-quarters full with warm water and a few drops of red food coloring. Add 6 drops of liquid detergent to the bottle, and 2 tablespoons of baking soda.
Slowly pour vinegar into the bottle and step back!
- Fill a child’s swim pool or sandpit with lots of slightly moist sand.
- Get the kids to each make a volcano sand mound with a hole in the center
- Place a small disposable cup in the hole; put in 1 tablespoon of baking soda plus 2 tablespoons of water in order to make it dissolve.
- Add 2 tablespoons of vinegar to which you have added a few drops of red food coloring, then watch it erupt!
You can repeat the activity over and over again.
1. Before the eruption event, form a piece of modeling clay about the size of a baseball into a mountain shape.
2. Put the shape on waxed paper.
3. Using your fingers, pinch the sides of the clay to form lumps that look like lava coming down the sides of the volcano.
4. Poke a hole in the middle of the volcano. Let the clay dry overnight.
5. Paint the volcano with brown paint. Let the paint dry thoroughly.
....To make your volcano active: Put 1 tsp of baking soda in the center of the volcano. Then add 1 tbsp of vinegar to make it erupt. Watch out!
Volcano #4 Materials you will need:
1/4 Cup of Vinegar
Red Food Coloring
Liquid Dishwashing Soap
1 Tablespoon Baking Soda
Modeling Clay (Plasticine)
Newspaper or Vinyl Table Cover
1. Clear a work surface and cover it with newspaper or a vinyl table cover.
2. Model a volcano out of modeling clay. You could use red clay around the top of the volcano to make it look like red-hot lava. 3. Make a hole at the top of the volcano.
4. Stir in 1 tablespoon of baking soda
5. Add a few drops of red food coloring
6. Add a few drops of liquid dishwashing detergent.
7. Get ready! Pour in ¼ cup of vinegar and stand back!!!
The eruption is acid meeting another substance called an alkali.
Fill a clear cup 3/4 full with vinegar. Add 1/2 teaspoon baking soda. Drop in a few kernels of unpopped popcorn. Watch as the kernels rise and fall.
Variations: Try substituting club soda for the vinegar and baking soda. You can also try using other objects like buttons or pebbles.
• Fill a shallow dish with water.
• Sprinkle talcum powder over the surface of the water.
• Dip a toothpick into Dawn dishwashing liquid.
• Dip the toothpick into center of water in pan.
• Watch the powder race to the sides of the pan.
• Variation: Try this same experiment with pepper instead of powder.
MOLD GARDEN #1
For some reason children seam to love watching mold grow. Here is a safe way to experiment with mold.
• Give children a small zip-lock bag and a piece of bread.
Have them place the bread into the bag and then add a teaspoon of water. Zip up the bag and set out the bag to observe. After a few days, mold will appear on the bread.
• Discard bags unopened, when experiment is over.
Variation: You may want to repeat this experiment, but this time make two bags of water and bread and put one in the center and one in the refrigerator. Which one grows mold the fastest?
GROWING MOLD #2
Materials you will need:
Some leftover foods (like bread, oranges, lemons, apples, grapes, red peppers, courgettes, cauliflower, cheese or biscuits)
A Clear Container with a Lid (A big glass jar or a big clear plastic container works best)
*** DO NOT USE: anything with meat or fish in it. After a few days these would start to smell very bad.***
NOTE: This is a great project to keep a log or notebook on your findings each day that you check for changes.
1. Place the jar on its side.
2. Cut around 3 to 5 different pieces of food into small chunks about 1.5cm (1 inch.).
3. Dip all the different pieces of food into the water.
4. Spread the foods out in the jar so that they are not in a pile.
5. Place the lid on the jar and tape around the outside of the lid to seal it
6. Place the jar where it will not get knocked over or thrown away.
7. Put a label with the date on the jar
8. Keep a check on the food in the jar.
• You probably won't notice any change in the food for the first few days; however, you should start to see some green, white or blue fuzzy/furry stuff growing there after.
• Still keep checking; after a few more days some of the food may start to rot and look gross. Now you can see how the mold spreads and how the food rots in just two weeks.
NOTE: After the two weeks, DO NOT open the lid. Throw the jar and its contents in the bin and DO NOT reuse the jar.
Molds do not grow from seeds. Molds grow from tiny spores that float in the air. Some of these spores fall onto a piece of damp food and then grow into mold. Adapted from: kids-science-experiments.com
FINGER PRINT LIFT: Here's an amazing trick that lets children try their hands at a little forensic science by lifting their own fingerprints.
1. Individually, have each childe press their fingertip on a pocket mirror.
2. Cover the entire print with graphite dust by rubbing a soft pencil with sandpaper.
3. Blow gently to remove excess dust.
4. Now carefully stick a strip of tape to the print and slowly peel it off. Stick the tape to a piece of white paper, and the print should be distinct. You can inspect the fingerprint under a magnifying glass, or just with the eye. If you go to the wiki website, I you can decide whether the fingerprints are 's' whorl, loop, or an arch.
ACID & BASE EXPERIMENT
1. Before the science event, boil 1 cup of shredded red cabbage until the water is dark.
2. Dilute it with water until medium purple.
3. The purple water will show if something is an acid or a base.
4. If the water turns light green or yellow color (after adding the substance), then the substance is an acid. And if it turns dark green or blue - it is a base.
Divide this liquid solution in several glasses. Have the kids guess what color the water will turn. Add baking soda (turns green), bleach (turns yellow), sprite (turns light purple), etc. Get litmus paper to check the acidity levels.
MAKE A 'NAKED EGG'--EGG IN VINEGAR EXPERIMENT (K-A tested; image by K-A)
A naked egg is an egg without a shell. Using vinegar, you can dissolve the eggshell--without breaking the membrane that contains the egg.
A container big enough to hold all the eggs; a cover for the container
A big spoon
1. Place eggs in the container so that they are not touching.
2. Add enough vinegar to cover the eggs. Notice that bubbles form on the eggs. Cover the container and put it in the refrigerator. Let the eggs sit in the vinegar for 24 hours.
3. Using the spoon, scoop the eggs out of the vinegar. Be careful--the eggshell has been dissolving. The egg membrane, which is not as durable as the shell, may be the only thing holding the egg together.
4. Carefully dump out the vinegar. Put the eggs back in the container and cover them with fresh vinegar. Leave the eggs in the refrigerator for another 24 hours.
5. Scoop the eggs out again and rinse them carefully. Throw out the eggs where the membranes have broken and are oozing out.
6. When complete, there will be an egg without a shell. It looks like an egg, but is translucent. The membrane will flex when squeezed.
An eggs shell dissolves when submerged in vinegar.
Vinegar contains acetic acid, which breaks apart the solid calcium carbonate crystals that make up the eggshell-- into their calcium and carbonate parts.
The calcium ions float free (calcium ions are atoms that are missing electrons), while the carbonate goes to make carbon dioxide.(Those are he bubbles that you see)
Note: The shell dissoled in 24 hours. Although directions say to put the egg in the refrigerator, I forgot to. (It still came out fine) The remainder of the experiment was followed as directed. After a couple days, you could actually see the yolk floating within the membrane. Both kids and adults liked this one! The egg feels rubbery--but it does 'splat' when dropped. Barb
THE ABOVE EGG EXPERIMENT--EXCEPT USING A 'HARD BOILED' EGG!
Directions are exactly as used in the above "Raw Egg" in Vinegar experiment... except you first boil the egg and let it cool.
The shell dissolved within 24 hours--the same as in the above experiment. I left the egg in the vinegar for a couple days to see if it would become transparent as when using the 'unboiled' egg. It did not.
What it did do was become bouncy. (See image as it bounced to and off the floor) Trying to get a good photographic image, the egg was literally dropped about 25 times from heights of up to four feet. The egg did not break but bounced after each drop.
The difference between the two egg experiments would be interesting for the children to observe and talk about. (Image by KidActivities.net)
This is science, art, and outside winter play!
ICE BLOCK DESIGNS
Younger children can observe how salt melts ice while creating colorful designs in large blocks of ice.
Need: Large blocks of ice, Coarse salt, Food coloring, Eye droppers
Freeze water in empty one gallon milk containers. Remove the cardboard when water is frozen.
- Place ice blocks on trays covered with several layers of newspaper.
- Sprinkle coarse salt on top of the ice blocks.
- Drip various colors of food coloring on top of the ice block--tunnels of color are created as the salt melts through the ice block.
- Put the colorful ice blocks outside. If cold enough- they should stay frozen for several days.
- Children can continue to examine the melting process during outdoor play. If possible-(and if they are interested) give kids their own block of ice.
- If you have a large group do this activity over a few days. Children will enjoy watching the changes that occur as the blocks melt away!(Image by KidActivities.net)
Idea dapted from Marjorie E. in KinderArt.com NOTE: When salt goes over the side of the ice block-it will quickly melt grooves into the sides. The color will travel down the grooves. KA placed the ice block in a tin pie pan with lots of paper to soak up excess colored water. The ice stayed solid (outdoors) for about a week. (It melted when we had a freakish 65 degree Michigan winter day in January!)