This theme gave me the opportunity to do my all time favourite experiment. I first saw this presented on TV in Cadbury's chocolate ad performed by Julius Sumner Miller and always wanted to do it. However I had to think how to best present this in a library setting. Professor Miller uses a flaming piece of paper which i didn't think appropriate in the library and also considering the OH&S implications.
However I came across I version using a birthday candle which although had an open flame, was more contained.
Science concepts/experiments:
Egg into a bottle trick.
I thought long and hard about how to do this safely in storytime. Have a boiled egg that is slightly too big to fit into a glass bottle. Put a candle into the top end of the egg and light it. Hold it underneath the upturned bottle so that it is heating the air in the bottle up. I got the children to count up to 30 (or you could get them to sing the Happy Birthday song twice). Then bring the egg up to the mouth of the bottle so that no air can get into the bottle. The candle will go out and then wait for the egg to be sucked into the bottle.
Why this happens: The flame heats up the air in the bottle which causes the air to expand. When the bottle is sealed with the egg and the candle goes out, the air cools and shrinks, pulling the egg with it and into the bottle. Here is a youtube clip demonstrating the experiment.
Raw or boiled eggs?
How to tell the difference between raw eggs and boiled eggs.
This demonstration involves spinning a boiled egg and a raw egg on a table. Once the egg is spinning well, stop it with your finger. Do this with both eggs and notice that they behave differently. The raw eggs will continue to spin once you stop it slightly, while the boiled egg will just stop. Take the egg you now know as boiled and tell the children you are so certain that this is the boiled egg that you will crack it on your head. It gets a big laugh because the children are not as sure as you are and if you are mistaken you will get egg on your face.
Why this happens: This is because the liquid in the raw egg is being effected by centrivical forces, that is, it continues to spin inside the shell of the egg when you stop it. Don’t believe it...find information here or a video here
Book Suggestions:
Hattie Peck - Emma Levey.
The cow that laid an egg – Andy Cutbill
Big fat hen - Keith Baker
Hunwick’s egg – Mem Fox
The odd egg - Emily Gravett
Out of the egg – Tina Matthews
Have you seen my egg? - Penny Olsen
Whose egg? – Jeanette Rowe
Big red hen and the little lost egg – Margaret Wild and Terry Denton
Craft suggestions:
Stained glass eggsEgg carton crafts
Chick in an egg
Hatching egg
Gotta try both these tricks at home!
ReplyDelete