3 fun science experiments to try this Christmas

This Christmas, Developing Experts shares our favourite 3 wintry science experiments that you can do at home or in the classroom.

We all know that kids get rather excited in the build up to Christmas.  But, what can you do to keep them busy before Santa’s sleigh flies into sight?  

Here at Developing Experts, we like to get inventive over the festive period, so try one of the 3 Christmas science experiments below and give Christmas some sciencey spirit!

Bauble Terrarium

In this activity you will build a terrarium that can be hung on your christmas tree. A terrarium is a self contained habitat for plant life. Your terrarium will be a sealed and self-sustaining world. It will continue to thrive as long as it gets sunlight.

For this activity you will need: a clear bauble (that either opens into two halves or opens at the top), soil, ribbon, moss, grass shoots, tweezers (optional), a tiny worm, a glue gun or rubber bands, and any other decorations you fancy!    

  1. Open your bauble and place in a layer of soil, so it is about a quarter full. Use a funnel for a bauble that opens at the top.    
  2. Now lay out your garden. This is entirely your design, but here are some tips:
    a. You may find it easier to place your items using tweezers.
    b. Adding moss will keep the terrarium moist and encourage other plants to grow. c. If you’re adding grass, try to pick the grass and its soil.  This means it will find it easier to grow.
    d. A tiny worm helps to move the soil around, and increase the longevity of the bauble.
    e. You can add small plastic decoration, but these will likely deteriorate over time.      
  3. Close up your bauble and seal it with either a glue gun or rubber band (coloured ones look nice). This is to prevent water from escaping and forces it to be recycled.    
  4. If your bauble is made of two halves, gently tap on the side as you slowly lift it upright.  This will help your garden stay intact.    
  5. Thread a pretty ribbon of your choice through the top and hang it in direct sunlight on your tree.

...the science bit

Because the terrarium is completely sealed and has everything it needs, the materials will be recycled again and again. It is a completed content mini-world. The sun will provide it with enough energy to keep growing and encourage new life.  Wow!

Expanding Marshmallow “Snowman”

This is a fun demonstration of what happens to objects in low pressure. In this activity we will be building an ‘Expanding Marshmallow Snowman’ and making him grow and shrink!

For this activity you will need: a large syringe, some mini-marshmallows, felt pen, pipe cleaners and cocktail sticks (optional).    

  1. Remove the plunger from the syringe and rest it so the the open end is at the top.    
  2. Design a ‘snowman’ from marshmallows. Remember that it will need to be dropped into your syringe, so not too big. You may want to stick the marshmallows together so that it keeps in shape.     
  3. The end of a cocktail stick makes a great nose and a small piece of pipe cleaner can be a stylish scarf.    
  4. The rest of the decorations can be done with felt pens.    
  5. Put your ‘snowman’ into the syringe. It might be easier to load it with the syringe leaning slightly. Replace the plunger and push it down but don’t squash the ‘snowman!’  
  6. Place your thumb over the opening of the syringe to seal it, and pull up on the plunger.    
  7. Voila! The expanding Marshmallow Snowman.   Snow joke, it really does come alive!

...the science bit

Marshmallows contain a lot of air (that's why they are so squishy and delicious). When you pull up on the plunger, you lower the air pressure inside the syringe. The air that is there tries to stretch out to fill the space, including the air inside the marshmallow. So we see our ‘snowman’ start to expand. 

The Magic Wallet

This is a simple engineer trick that makes money appear to flip from one side to the other. It is a great novelty to make but can also be given as a gift or card.

For this activity you will need: two pieces of card the same size, scissors and tape.    

  1. Fold the shorter edges together on one sheet, create a hard crease and cut it into two halves along the crease.    
  2. For the second page, fold the longer edge together twice and cut this into four strips of equal length. You will only need three of them.    
  3. Weave the strips between the two halves, so that the outer strips go over on half and under on the others. The middle strip should do the opposite.    
  4. Square the paper and strips so that the edges meet and tape the edges together.    
  5. Fold the wallet in half one way, then the other.    
  6. Decorate it until your heart’s content.    
  7. Slip in a note or small object, close it and open from the other side. It has flipped.  What a festive treat!

...the science bit

The method that weaves the paper together is responsible for the effect. When folded in half, all the strips lay over the top of the object. Opening it one way will lift up the two outer strips and the other way will lift the middle strip only. With some sleight of hand you can create the effect of the object jumping.

Give one of these santa-stic science experiments a go over the christmas holidays and keep the kids engaged with learning along the way!


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