Everyone knows it’s dangerous to play with electricity. If a strong enough electrical current runs through your body, it can overpower the electrical messages your body sends to your brain, or even stop your heart!  Fortunately, kids science has some easy elementary science experiments you can do that are safe to try at home.

Experiment 1: Dancing dots

1. Tear up a few pieces of paper (tissue paper works best) into little dots and spread them out in a pile.
2. Wet a plastic comb or brush and run it several times through your hair.

3. Bring the comb close to the paper dots. If you brushed your hair enough, the dots should dance!

What’s Happening?

Everything in the world, including your hair, is made up of tiny particles called atoms. An atom is made up of a hard clump of positive (+) protons, surrounded by whizzing negative (-) electrons. There are usually the same number of protons and electrons in an atom, so they cancel each other out.

When you run the comb through your hair, the comb starts grabbing electrons from the atoms in your hair. When there are more electrons than protons on the comb, you create a negative electrical charge.

The paper dots are attracted to the negative charge, and the paper is light enough that you can use the comb to pick them up.

Try touching the comb with a finger of your other hand. What happens?  The dots all fall off!  This is because the extra electrons in the comb move into your finger. If there’s no negative charge on the comb anymore, there’s nothing to hold the dots on, and they will fall.

Experiment 2: Water Wizard

1. Turn on a faucet until you have a very thin stream of water. The thinner the better.
2. Run a plastic comb through your hair several times.

3. Hold the comb near the water. The water should bend toward it!

What’s Happening?

The neutral particles in the water are attracted to the negative charge you built up on the comb.

Experiment 3: Build a Battery

This experiment is a little more complicated, but the things you need should be available at a hardware store. You will need:

• citrus fruit (like oranges or lemons) or a potato
• something copper (like a nail or coin or metal strip)
• a piece of zinc (about the same size as your piece of copper)
• 2 wires with crocodile clamps

• a small LED light or a voltmeter

1. Press down on the fruit and roll it around on a hard surface to break open the juice inside.
2. Get an adult to help you make a small cut into the skin of the fruit and push the copper in.  Leave the end of it sticking out.
3. Make a small cut into the other side of the fruit and push the zinc in.
4. Connect the end of your first wire to the copper, and the end of your second wire to the zinc.

5. Connect the other ends of both wires to the LED or voltmeter. You should see an electric charge!

What’s Happening?

Combining metal with acid (like lemon juice) causes a chemical reaction that creates positive and negative particles around each piece of metal. The negative particles will move through the wires from one piece of metal to the other, which causes an electric current. If the reaction is strong enough, it can even power a light bulb!

Post by Sarah

Hey kids, close your eyes for a moment and imagine that your arms are stuck to your sides and your legs are stuck together. Imagine that you have no ears, and that you smell with your tongue. And imagine that your entire body is covered with fingernails.

Seems strange, doesn’t it? Now you know what it’s like being a snake!

Snakes are a group of reptiles closely related to lizards. Most people think that the big difference between them is that lizards have legs and snakes don’t, but there are some legless lizards, and some snakes that have little “claws” near their tails which are actually the remnants of hind legs!

Actually, the biggest differences between snakes and lizards are the ears, eyes, and scales.

Snakes don’t have eyelids like lizards do. Instead, their eyes are covered by a clear, hard scale. If something gets in a snake’s eye, the snake licks its eyes clean using its tongue!

Snakes also don’t have ear openings on their heads at all! Instead, snakes hear though vibrations that travel though the air and the ground. So if you want to frighten away any snakes, all you need to to is stamp very hard as you walk.

Snakes don’t use legs to get around, either. They move by slithering with their bodies, and using their scales to help hold them in place.  Snake scales cover their entire bodies, and the widest scales are on their bellies. Their scales sit in your skin just like fingernails do, and help to grip the ground as a snake moves.

Because they are also hard, like your fingernails, scales don’t stretch as a snake grows. That’s why snakes have to shed their scales as they grow. They crawl out of the old, too-small skin, and leave it behind like a long sock!

Fun fact #1: Biggest Snake: You can divide snakes up into two groups: those who catch their prey by biting them with poisonous fangs, and those who catch their prey by squeezing. The biggest snakes are the squeezers, or constrictors. The title for biggest snake is shared between two species: anacondas and pythons. Anacondas are the heaviest snakes, and can weigh up to 550 pounds. Reticulated pythons are the longest; they can reach up to 10 metres (33 feet) long. That’s like laying eight 10-year-olds end-to-end!

Fun Fact #2: Most Poisonous Snake:  The Taipan is a snake that lives in Australia, and its venom will clot your blood, turning it into a thick soup, and destroy all your organs. It also doesn’t need a lot of venom to do that.  Terry Phillip, a curator at Reptile Gardens, says: “1 milligram of the venom is equal to 1 M&M candy cut into 1,000 equal pieces and [one of those pieces] is how much it takes to kill one adult human being.” That is one deadly snake!

Fun Fact #3: Greatest Actor: The hognose snake is a burrowing snake that is harmless to humans, but if anything threatens it, it will flatten out its head, rear up, and hiss, just like a cobra! Better yet, if that doesn’t work to scare off the threat, the hognose will roll over on its back and play dead with its tongue hanging out of its mouth. Even if you flip it over onto its belly, it will just roll on to its back again!

Post by Sarah

Hey kids, have you ever wondered why you hear thunder after you see lightning? Or why the horn on a car sounds different when it’s coming toward you than when it’s moving away? Or why things sound different under water? It all has to do with sound waves!

Anything that vibrates makes a sound. Try this: put your hand gently against your throat and hum. Can you feel those vibrations? That’s your voice!

The faster something vibrates, the higher the sound is. And the bigger the vibrations, the louder the sound is. When something vibrates, it smashes into the particles of air, liquid, or solid around it. These particles then smash into the particles next to them, and send the sound along in a wave.

You can see the way sound travels by filling up a tub or sink with water. Put your hand in the water and give it a quick wave. See how the wave your hand made travels through the water? Sound travels in just the same way!

Sound also travels differently depending on what it’s moving through. If you had a microscope more powerful than anything on the planet, you would be able to see that everything around us is made up of tiny particles called atoms. The atoms in a gas, like air, are far apart and whizzing around. The atoms in a liquid are closer together, but slosh past each other. The atoms in a solid are packed tightly together and locked into one shape.

When sound waves travel through air, the atoms are spaced so far apart that it’s hard for one group of atoms to reach the next group to pass the sound wave along. Sound waves in air fade away very fast.

Because the atoms in liquid are much closer together, it’s much easier for them to bump into each other and pass the sound wave along. But the best thing for sending sound waves along is a solid. Have you ever seen a movie where someone puts their ear to the ground to see if someone is following them? That’s because solid rock carries sounds faster and farther than air!

You can try this experiment with a friend. Find a long metal fence, and stand at either end of it. Put your ear to the fence, and have your friend tap the other end with a rock or stick. You should be able to hear the sound twice – once through the fence, and again through the air!

You can also hear that sounds are much louder in solids than in air. That’s why spies in movies will listen to a conversation though a wall by putting their ear against a glass. The solid glass makes the sound louder!

You can have some learning fun of your own with this simple experiment: Get in a bathtub (or something you can swim in), and tap the side of the tub with something hard. Then put your head underwater and tap again. The sound should be louder in the water! Now put your ear against the side of the tub and tap a third time. The sound will be even louder!

So remember next time you’re dancing to your favorite songs to take a look at the speakers and watch the vibrations. Those simple smashing atoms can make some really amazing beats!

Post by Sarah

Hey kids, can you think of something an animal makse that can stretch 1½ times its original size, is incredibly lightweight, and is stronger that steel? The answer is spider silk!

Spiders are amazing animals. Although there is one vegetarian species of spider we know of, most spiders are deadly predators. They stalk prey on their eight legs, and when they catch a juicy insect, they wrap it up in silk, pierce it with their fangs, and pump it full of deadly venom. The venom paralyses the prey, and the spider uses a special digestive fluid, like stomach acid, to turn the insides of the insect into a liquid that the spider can slurp up as a snack!

Most spiders have four pairs of eyes – two big eyes and six little eyes – that they use to help them spot their prey. Jumping spiders leap for their prey, and can jump up to 50 times the length of their bodies! That would be like you making a jump of about 76 metres, or 250 feet!

Trapdoor spiders dig a hole in the ground and then cover it with a lid on a hinge of spider silk. They hide inside the hole, and when an unsuspecting insect wanders by, they leap out and grab it!

But one of the most amazing and interesting facts about spiders is that they can spin a web of sticky strands to catch their prey. When an insect gets stuck in a web, vibrations the trapped insect make send a message through the web to the spider telling it exactly where to find the intruder.

Spider silk is incredible stuff. If you make a wire out of steel as thin as a strand of spider silk, the spider silk is stronger. The steel would snap under pressure, but the spider silk can stretch up to 1 ½ times its size, and it’s so light that if you stretched spider silk into a strand long enough to wrap around the whole Earth, it would only weigh 450 grams!

But silk isn’t just used for hunting. Baby spiders make non-sticky silk into a parachute that lets them drift around on the wind. Spiders attach themselves to their webs with a strand of dragline silk, that catches them if they fall just like a bungee cord. They can even make a stiff, hard kind of silk to wrap up a sac of eggs that will hatch into thousands of baby spiderlings.

Here are some more interesting facts about spiders:

The Goliath Bird-Eating Tarantula sounds scary, but it’s pretty harmless to humans. In fact, a tarantula bite is about as bad as a bee sting. But this spider is the biggest in the world — as big as a dinner plate! It can shoot sharp, irritating hairs from its body at anything it thinks is a danger (including humans), hisses at a threat so loudly that you can hear it 15 feet away, and can eat anything from beetles to frogs, small snakes, lizards, bats, and even climbs into nests to grab baby birds!

The smallest spider in the world is almost impossible to spot. It’s called Patu digua, from Borneo, and it’s so small at 0.37 mm that it would easily fit on the head of a pin!

The most venomous spider in the world actually has a Guiness World Record. The Brazilian wandering spider has venom so dangerous that a tiny drop, only 0.006 mg, is enough to kill a mouse!

Post by Sarah