The challenge (the final in the eight-challenge series) was for the students to predict, with an explanation, the difference in the extent to which four different samples of microwave-popcorn pop.
The samples were:
- one completely dried in the oven and soaked in cooking oil overnight
- one completely dried in the oven and soaked in ethanol (alcohol) overnight
- one completely dried in the oven
- one not treated in any way
To make the tests valid, the following variables were kept constant
- the number of kernel in each sample
- the power setting on the microwave oven
- microwave duration
Can you think of other variables that would have been kept constant or anything that we had to be mindful of when conducting this test?
As for a measurement of/determining the extent of popping, instead of me telling them, my students came up with a method.
What do you think was their strategy?
(I can think of at least two! How many can you think of?)
What would you have predicted? Why? Hint: Find out how microwave ovens work and the kind of materials that can be microwaved and why.
In this particular challenge both the Beauties and Brawn did equally bad — they both lost a point. I can’t remember why though; it has been six years after all!
An extension could be to study the effects of soaking it in different alcohols — methanol, ethanol, propanol etc., not the variety you can find at a liquor store or a bar, silly! 😉
Knowing how microwave ovens work, you could also try to determine if the effect can be — or is — directly related to a characteristic of the alcohol.
What that characteristic is — or might be — you’ll have to figure out yourself! 🙂 I am nice aren’t I?! 😉
Note for Teachers
Where a microwave oven is not readily available, you could easily conduct this experiment over an electric heater. Definitely NOT over an open flame!! Ethanol could be replaced by the variety that is available at a liquor store or even at home! 🙂 You will, for sure, encounter some challenges doing so, but not insurmountable!
As a matter of fact, a lesson discussing, with students, how to conduct this investigation using an electric heater in itself would be a fruitful one. The focus in this case wouldn’t be micro-waves, obviously!