Thursday, August 15, 2013

Lots of Questions - Part 2

Here are some more intriguing questions sent in by members of Skooville – the place where children learn to be safe online.

The next two question go nicely together because they you can find the answers yourself!  You get to conduct your very own experiments which will give you the answers you are looking for.  But don’t worry – we’ll talk you through it.

Q from Olinka:  What will happen if you store bacteria in a container and then put one container in a warm area and one container in a cold area? Which bacteria will spread more?

A: In science labs they grow bacteria in a material called agar on petri dishes.  These are expensive and a bit hard to get at home.  So here is a cheaper way to find out the answer to your question.

You will need:

·        2 Slices of bread.  Any type of bread is good, even the cheap white stuff.  Just make sure both bits are from the same loaf.
·        2 Zip lock bags.  Big enough to fit one slice of bread in.
·        A ruler
·        A fine tip permanent marker pen

Instructions:

1.      On each bag draw a grid which covers one side of the bag.  Make the squares in the grid 10 mm square.
2.      Place a slice of bread in each bag.
3.      Put one bag in the fridge.
4.      Put one bag somewhere warm like the hot water cupboard.
5.      Once a day look at each bag and see if the is any bacteria growing. By using the grid you can record how much is growing on each sample each day.
6.      It might be a good idea to take a photo of each bag each day.  That way you can see the changes and the difference between the bags.


Q from Clavance:  Does bicarb soda over fill when mixed with vinegar?

A: Most of us know that when you mix vinegar and baking soda together, there is a fizzing reaction. But your question highlights the importance of predictions and testing followed by learning from our observations. So let get guessing!  .

You will need:

A small glass approximately 250 ml
A large jug approximately 1.5 litres
Baking soda
White vinegar
Tablespoon

Instructions:

1.      Pour 150 mls of vinegar in the small glass. 
2.      Pour 150 mls of vinegar in the large jug.
3.      Get ready to put a tablespoon of baking soda in the jug AND the glass.  BUT …

Before we do… let’s make some predictions.

Write or talk about the following questions…

What is going to happen?
Will it make a mess?
Will the glass be big enough?
Will the jug be big enough?

Now we get to test out our predictions!  Add the baking soda to each container.

Don’t forget to watch (observe) what happens and record what you see.

So now we can use our observations to answer the original question “Does bicarb soda over fill when mixed with vinegar?”

Science is great as we can learn from making guessing.  We try it out by doing an experiment.  Then we watch what happens.  The fun really starts when we use the information we have gathered to provide an explanation. 


We could go on but we have some mouldy bread and stinky vinegar to clean up!  But don’t worry, we’ll be back with more questions and answers soon!

______________________


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