There are certain simple experiments which really impress children. They might not entirely understand the explanation which lies behind them, but they’ll remember them for their whole life, and they could very well help them understand something inscience class when the time comes.
Wecompiled 11ofthe most interesting experiments which are guaranteed toimpress your kids and friends. Everything you need for them can befound athome.
Pencil trick
You need: Apolyethylene bag, some ordinary pencils, water.
The experiment: Fill about half the polyethylene with water. Pierce the bag using the pencils inthe places where it’s filled with water.
Explanation: Ifyou pierce the bag with the pencils and only then pour inthe water, itwill seep out through the holes you’ve made. But ifyou fill itfirst and then insert the pencils, the water will not seep out atall. This isaresult ofthe fact that when the polyethylene isbroken apart it’s molecules move closer together. Inthis case, the polyethylene tightens around the pencils.
Uninflated balloon
You need: 2balloons, ahandful ofpins (orabed ofnails).
The experiment: Ifyou take aninflated balloon and put itonjust one pin ornail— asexpected, it’ll pop. However, ifyou take ahandful ofpins and lay them out flat and then take another balloon trying todothe same thing again, this time you can push the balloon down onto the pins and itwon’t burst. Abed ofnails can substitute the pins. You can even put abrick onthe balloon (but donot topush too hard).
Ifyou try this experiment, please, becareful, you may want toconsider wearing safety gloves and eye protection.
Explanation: When you increase the number ofpins you push into the balloon you reduce the pressure oneach pin and hence the balloon doesn’t pop.
Colourful cabbage
You need: 4glasses with water inthem, food colouring, some cabbage leaves.
The experiment: Add different coloured food colouring toeach glass ofwater, then place asingle cabbage leaf inthem. Leave them overnight. Inthe morning the leaves will have changed colour.
Explanation: Because plants absorb water, their leaves also absorb the colour ofthat water. This isknown asthe capillary effect, whereby the water will pass into the tiniest tubules ofthe plant. This happens with flowers, grass and even trees.
Fireproof balloon
You need: 2balloons, acandle, matches, water.
The experiment: Fill the first balloon with air and hold itover alit candle todemonstrate tothe kids that the flame will cause ittoburst. Then fill the second balloon with tap water, light the candle and hold the balloon over itonce again. You’ll see that inthis case the balloon can withstand the heat ofthe flame.
Explanation: The water inthe balloon absorbs the heat given out bythe candle, sothe material ofthe balloon itself doesn’t burn and then burst.
Floating egg
You need: 2eggs, 2glasses ofwater, some salt.
The experiment: Carefuly place anegg inaglass ofordinary pure water. Provided the egg hasn’t gone off, itshould fall tothe bottom ofthe glass. Then pour some hot water into the second glass and dissolve 4-5 tablespoons ofsalt init. Itwill work better ifyou wait until the water then cools down. Then drop the second egg init. Itwill float onthe surface rather thank sink tothe bottom.
Explanation: The key here isthe density ofthe molecules making upboth the egg and the water. The average density ofanegg ismuch greater than that ofpure water, soit’s pulled downwards. The density ofthe salt mixture ishigher than that ofthe egg, sothe latter can’t fall tothe bottom.
Striking amatch with arubber band
You need: Two matches, arubber band
The experiment: Wrap arubber band around two matches, knotted around one and slipped over the other. Lay the first match onits side, pull itback and stretch the rubber band. Hold the other match inthe vertical position with your other hand. When you let goofthe rubber band, the match flies like anarrow and strikes the one you’re holding.
Explanation: The match ignites when you apply pressure tothe striking match, rubbing the phosphorus coating with the band.
Your own avocado tree
You need: anavocado pit, 4toothpicks, aglass ofwater.
The experiment: clean the pit ofafresh and ripe avocado, press the toothpicks into the pit around the middle, and balance itonaglass ofwater the pointy sideup. The bottom ofthe pit should sit inthe water. Let itrest like this for acouple ofweeks, keeping itatroom temperature and refilling the water asneeded. Soon the pit will sprout roots and then eventually crack inhalf with asprout coming out from the top. Once itsprouts, you can place itinamore comfortable pot togrow.
Explanation: the toothpicks allow the pit tobalance, obviously, without the bottom touching the glass, which would otherwise prevent roots from growing normally. And all the rest isjust the force ofnature!
Crystallised candy
You need: 2glasses ofwater, 5glasses ofsugar, small wooden kebab sticks, some thick paper, some clear glasses, asaucepan, food colouring.
The experiment: Make some sugar syrup byadding acouple ofteaspoons ofordinary sugar toaquarter glass ofwater. Sprinkle apiece ofpaper with some sugar. Dip the kebab sticks inthe mixture, stirring them sothat pieces ofsugar start tostick tothem. Make sure the mixture isspread evenly along the stick, then lay them out onthe paper.
Leave the sticks todry out overnight. Inthe morning, dissolve five glasses ofsugar intwo glasses ofwater inaheated saucepan. Leave the resulting syrup tocool down for 15minutes, although not for too long asotherwise the crystals won’t form. Then pour itinto some empty jars and add food colouring indifferent colours. Place the now-ready kebab sticks inthe jars, but make sure they touch neither walls orbottom— use aclothes peg todothis.
Now wait and observe what happens.
Explanation: The solubility ofthe syrup-water declines asits temperature falls, which produces asediment ofsugar grains onthe sticks.
Alit match
You need: Some matches, atorch.
The experiment: Light amatch and hold itabout 10-15 centimetres away from the wall. Shine atorch over your hand holding the match. You’ll notice that only the shadow ofyour hand and the matchstick itself will appear onthe wall— the flame will not appear.
Explanation: Fire does not produce ashadown, because itdoesn’t impede the passage oflight through itself inthe same way that physical materialsdo.
Levitate adollar bill
With this video, you can learn how toperform the floating money trick. It’s very easy todo, and itwill impress your kids— nomagic, just physics!
