momatwork
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Joined: Wed Nov 28, 2007 12:46 pm

Mummification of an apple

Postby momatwork » Wed Nov 28, 2007 1:15 pm

Hi,
My daughter's science fair project for mummification of an apple started out simply enough, but now I am confused. I originally thought this was observation type only experiment, however, her teacher said he wanted 30 samples to be tested, so instead of a whole apple being used, we cut the applies into smaller pieces to have 30 samples. We have different salts that these apples pieces are sitting in being mummified to tell which combination of salts worked best (salt, baking soda, sodium carbonate, and the remaining combinations). Yesterday, we were told that the data needed to be plotted on an x, y coordinate graph. I am confused how to do this. I know that we have multiple variables, but how can you plot an observation? Only the apples in salt look normal in color, although somewhat shriveled. This bag has the most water in it. None of the other seem to have any liquid collected except in the salts. We did not measure the bags since not all of them had the same amount of salts inside. Any assistance would be very helpful! Thank you.
Mom

Craig_Bridge
Former Expert
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Joined: Mon Oct 16, 2006 11:47 am

Postby Craig_Bridge » Wed Nov 28, 2007 7:00 pm

Since the teacher is imposing a specific requirement that doesn't make sense to you for this particular experiment (or me based on what you provided), it is time to ask the teacher.

That said, you may have a bigger problem with "experimental design".

What was the hypothesis?

When you design an experiment to test a hypothesis, you need to figure out how you can quantify the results. If the hypothesis doesn't lend itself to any non-subjective measurements, then you might want to modify the hypothesis into something that can be measured.

If the requirements are to plot something in two dimensions, then you need to figure out what variable to plot on the independent axis (time or an independent experimental variable) and what to plot on the dependent axis (some measured or resultant variable).

All of this SHOULD be figured out before you start the experiment.

Unfortunately many parents and students don't start by trying to understand the scientific method see links for "scientific method" and "your question" on http://www.sciencebuddies.org/mentoring/project_guide_index.shtml and end up doing a lot of work that turns into a demonstration project vs a scientific investigation.
-Craig

momatwork
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Joined: Wed Nov 28, 2007 12:46 pm

Apple Mummification

Postby momatwork » Thu Nov 29, 2007 8:27 am

Thank you for your reply. I have quickly discovered that science fair requirements given in the middle of procedures does not make for a great and complete experiment. I had my daughter cut more apples into slices, mix new batches of the salts, but then we measured the apples 110 g for each bag. After day one, the apples were weighed and most of the apples lost about 30 g of water to the salts. We also photographed the appearance of the apple slices as she wrote the observations. I think that we can use this information to make our x, y graph after we observe the apples over time. My new question is this: can more salts be added each day as the water is absorbed due to saturation without messing this up? I do understand the whole experimental design was flawed from the beginning by not knowing the components. Her hypothesis was "If all of the salts absorb water independently, then the baggie containing the most salts should mummify an apple best."

geoffbruton
Former Expert
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Joined: Mon Aug 29, 2005 10:02 am

Postby geoffbruton » Thu Nov 29, 2007 10:02 am

Hi momatwork,

Sorry to hear of all your troubles with this project. I do think, however, that you are now on the right track!

Craig Bridge gave some excellent advice - and if at all possible, could you please post the original project information and method, or the URL if it came from a website?

With regards to the addition of more salt(s) to the bags, this will depend upon what the aim of the project was. For example, you have already monitored the loss of water over one day, by weighing the apple slices both before and after. Do the apples look completed dessicated? If you were to add more of the same salt(s) to the bag (assuming that they were now completely saturated with moisture drawn from the apples), you could continue to monitor the water loss at regular intervals over subsequent days. This would then give you some great data (either as an actual figure or as a percentage) which you could plot on an x,y graph! There will come a time in your experiment when the water loss slows and eventually stops - the apple slices are now completed dessicated.

One of the conclusions you might be able to draw from this data would be which salt(s) produced the most rapid water loss by comparing data from one dessicant to the next. Does that make sense? One thing that you should do (if you haven't done this already), is to perform multiple runs under the same conditions. For example, if one of your salts is sodium chloride (common table salt), you should perform several tests using this salt; if another salt was baking soda, this should also be carried out several times. This will allow for any variability between tests and hopefully produce more meaningful data. Your results could then be averaged and plotted on a graph. Keep in mind that these tests can be ran simultaneously - you do not need to perform them one after the other.

Alternatively, if the project was designed to show which salt(s) could absorb the most moisture, keeping the amount of salt constant (and known) would be important. It doesn't sound as though that is the purpose of this project, it was just something that occurred to me when you were discussing the variables.

The idea of photographing the apple slices at regular intervals is an excellent one! These would make a great display for the project.

Best of luck with the project - it sounds as though you are putting in a great deal of effort and thought, all of which will pay off, I'm sure!

Any questions, please just let us know.
Geoff.
Geoff Bruton
Firearm & Toolmark Section
Ventura County Sheriff's Department
Forensic Sciences Laboratory

momatwork
Posts: 3
Joined: Wed Nov 28, 2007 12:46 pm

Mummification of an apple

Postby momatwork » Thu Nov 29, 2007 12:07 pm

THANK YOU! I feel that this will do it. I appreciate all the help and guidance. I have this website marked as a source now and it will help us for the many years of science fair projects/experiments to come. I can't wait to share this information!
Linda

lovesanimals
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Occupation: student

Re: Mummification of an apple

Postby lovesanimals » Mon Oct 27, 2008 11:54 pm

I don't know if geoffbruton will receive this posting, but I wanted to let you know that my experiment with the Apple Mummification came in 2nd for my school's science fair. My mother performed the experiment changing the types of apples used and she increased the length of the days for drying the apple slices out. Her class came in 2nd in the city. So, I and my mom both wanted to say how much we appreciated your help and kind words. We were thrilled!!!!! Now that we have another project due, we have come back to the best resource on the web. THANK YOU VERY MUCH!

geoffbruton
Former Expert
Posts: 123
Joined: Mon Aug 29, 2005 10:02 am

Re: Mummification of an apple

Postby geoffbruton » Tue Oct 28, 2008 8:49 am

Good morning, lovesanimals,

That is AWESOME news!! Well done to you both! Thank you so much for the feedback - we all very much appreciate your comments, and are delighted to hear that all your hard work paid off.

Best of luck with your new project, and please let us know if there is anything we can do to help.

Thanks again,
Geoff.
Geoff Bruton

Firearm & Toolmark Section

Ventura County Sheriff's Department

Forensic Sciences Laboratory


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