Eggs and Easter

To incorporate some fun experiments in an egg or Easter themed storytime session.

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 eggs
Egg carton crafts
Chick in an egg
Hatching egg

Sinking and Floating

To experiment with objects that sink or float, and foster curiosity as to why.

Many children know about floating and sinking as they have experienced this frequently, either in the bath or in the pool. Floating objects are fun to play with but children may not have come to a realization as to why things float or sink and so this demonstration can be a fun learning experience.

This theme could also tie in with a pirate storytime and you could set up a clear water container with sand at the bottom and a treasure chest. 

Science concepts/experiments

 

Water experiment
What types of objects float and what sinks?
Fill a large see-through bowl or container with water.
Collect a variety of different items to test is they sink or float.  Corks, coins (look at small coins compared to large coins), pencils, feathers, paper, stones etc.  Get the children to vote on whether they would sink or float.

Compare the properties of some of the objects.  For example a small coin and a cork weigh about the same however they act differently in the water. Ask children if they have any ideas of why this would be.
Discuss that what objects are make of is important.
Discuss the size of objects and whether you can tell if it will sink of float.
Look at objects that may absorb water such as a sponge or paper which will float for a time but then sink.

Some fun 'tricks' to try in your water container
Find a volcanic rock (pumice rock)and an ordinary rock of a similar size.  The volcanic rock will float as it is filled with air.
Test out a Coke can as compared to a Diet Coke can. You can see what happens here 

Diver in a bottle 
Equipment: plastic bottle, pen lid (not one with a hole in it), plasticine/bluetac.


Fill bottle almost to the top.  You will need to add plasticine to the stem of the pen lid and place in the bottle.  If the lid sinks, remove from bottle (you will probably have to remove all the water just to get the lid out) and remove some of the plasticine.  You need to get the pen lid to just float on the top of the water.  Once this is achieved fill the bottle to almost the top and screw on bottle top well.
Squeeze the sides of the bottle.  What you should see is the pen lid 'diver' sink to the bottom of the bottle.  When you release the bottle the 'diver' returns to the top.


What happens in this experiment is that there is a small air bubble trapped at the top of the pen lid.  When the bottle is squeezed it increases the pressure inside the bottle which decreases the size of the air bubble and the 'diver' sinks.  Once you stop squeezing there original pressure returns, the air bubble expands and the 'diver' rises to the top.  More information on this experiment can be found here


This experiment pairs well with the book Ruby learns to float by Phillip Gwynne where the story talks about Ruby breathing in in order to float.  Talk about how air is needed to float and then explain why the diver sinks. 

Book ideas:

 

What floats in a moat? – Lynne Berry
Ruby learns to swim – Phillip Gwynne
Who sank the boat? – Pamela Allen
Mr Archimedes Bath – Pamela Allen

Craft:

Make a paper boat

Extra Learning:

During craft time some of the children came up and played with the container of water testing out the objects for sinking and floating. I encourage this curiosity in the children.  Some of the children decided that they could float the boats they made.  They discovered the the boats would sink for a while and then sink.  A lot of the children went home with soggy boats!