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Q & A: Popcorn puzzle

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Most recent answer: 10/22/2007
My exact question is: how many atoms are in a pop corn, before and after popping.

This question was formulated by one of my students who asked me the exact numbers of atoms in a pop corn.

To do the question more easy, we can omit the salt grains. So we have clearly a pop corn, without any salt. We can concentrate just in the corn and its matter (atoms).

The question is complicated due the following:

A standard pop corn have two different sizes. A small size (before pop) and a bigger size when popped, due the hot action.

So the exact number of atoms are exactly the same when the pop corn have the small size (before popping) and afterwards (when popped)?

When it pops and have a bigger size, the number of atoms have increased?

If the number of atoms have increased when the pop corn have a bigger size (popped)... how is this possible, if the initial size was smaller (before pop) and it had a fixed quantity of matter?

When popping the corn is bigger than before, so the quantity of matter is exactly the same before and after (independently of the corn size)?

And which is the exact number of atoms before and after popping.

Thanks in advance
- Xavier Dolz (age 31)
There is a nice article in Wikipedia about the mechanism of popcorn   

As to the number of atoms before and after, they are the same.  The huge difference in volume is due to the fact that the atoms (molecules) are much farther apart in the popped version.



(published on 10/22/2007)

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