Monday, 2 February 2009

Density of the Earth

Our latest Earthlearningidea is 'From an orange to the whole Earth: using an orange to model different densities of the Earth's layers'. Ask your pupils:-
- what will happen if you put a whole orange into a container of water?
- what will happen when you peel the orange and put the orange without its peel into water?
- what will happen when you put the orange peel into the water on its own?
Scientists know that the relative density of the whole Earth is 5.5 but the rocks of the Earth's crust have a much lower average relative density of 3.00. What does this tell you about the density of the layers inside the Earth?
This is a simple activity to carry out; tell us how you get on.


Anonymous said...

I just want to say how wonderful your activities are for pupils. I have been trying as many as I can. The best way to learn about Earth science!!

Anonymous said...

The orange - Earth activity is a bit tricky. Not all the oranges without the skin immerse deep into water, but there is a small difference only.

Anonymous said...

Reply to the comment above from Jothi - We found that some of the smaller oranges did not sink. It always seems to work well with large oranges.

Brett said...

Worked great for me with big, round, Florida navel oranges. I used it also as an opportunity for making and testing hypothesis. My students even started to design experiments of their own... will it sink if it has holes poked all over it? Will it sink if it has been submerged in water overnight?