Science Week
DO try these at home!
Blowing up balloons
What you'll need:
Balloon
About 40 ml of water
Soft drink bottle Drinking straw
Juice from a lemon 1 teaspoon of bicarbonate of soda
What's happening?
Adding the lemon juice to the bicarbonate of soda creates a chemical reaction. the bicarbonate of soda = a base
the lemon juice = an acid
When the two combine they create carbon dioxide (CO2). The gas rises up and escapes through the soft drink bottle, it doesn't however escape the balloon, pushing it outwards and blowing it up.
Ping Pong Ball Float
What you'll need:
A ping pong ball
A hair dryer
What's happening?
The airflow from the hair dryer pushes the ping pong ball upwards until its upward force equals the force of gravity pushing down on it. When it reaches this point it gently bounces around, floating where the upward and downward forces are equal.
gravity
upward force
Kinetic sand
What you'll need:
Kinetic sand
What's happening?
This is a 3D building toy made of:
98% sand and 2% polydimethylsiloxane (a type of silicone oil) that mimics the physical properties of wet sand.
Disappearing water
What you'll need:
•3 plastic cups
•1 nappy
•water
What's happening?
The third cup contains some contents of a dry, clean nappy. This contains a material called sodium polyacrylate, a water‐absorbing polymer.
Floating Egg
What you'll need:
One egg
Water
Salt
A tall drinking glass What's happening?
Salt water is denser than ordinary tap water, the denser the liquid the easier it is for an object to float in it. When you lower the egg into the liquid it drops through the normal tap water until it reaches the salty water, at this point the water is dense enough for the egg to float. Gravity‐free Water
What you'll need:
•A glass of water
•A piece of cardboard What's happening?
Even though the cup of water is upside down the water stays in place, defying gravity! With no air inside the glass, the air pressure from outside the glass is greater than the pressure of the water inside the glass. The extra air pressure manages to hold the cardboard in place, keeping you dry and your water where it should be, inside the glass. Invisible Ink
What you'll need:
Half a lemon Water
Spoon
Bowl
Cotton bud
White paper
Lamp or other light bulb
What's happening?
Lemon juice is an organic substance that oxidizes and turns brown when heated. Diluting the lemon juice in water makes it very hard to notice when you apply it the paper, no one will be aware of its presence until it is heated and the secret message is revealed. Other substances which work in the same way include orange juice, honey, milk, onion juice, vinegar and wine. Lethbridge Science Fayre
Thursday 12th January
2.30pm – 3.15pm
New hall