Science Buddies: "Ask an Expert"

I really need help in making up 2 more questions on my science fair project but i am out of ideas. My science fair project is How can lemon juice and heat source create invisible ink? I really need more help in making up 2 more questions that i can research in the internet and make a paragraph about. PLEASE HELP ME. my science fair outline with these 3 questions is due 1/6/09. Thank You so much and I would really appreciate your help.

Hi,

You might look through this prior discussion thread for ieas:

https://www.sciencebuddies.org/science- ... =31&t=4890

Best regards,

Barrett L. Tomlinson

Dear Gabynico731,

I am not sure what you mean by "questions that you can research." Do you need to add a dimension to your experiment? Do you need to ask questions about the ingredients or the reactions that are taking place? For example, why did I use the materials that I used and are there other materials that could have been more effective? Please explain what you mean so that we can provide more complete answers.

Michelle

Hi Gaby,

Melissa and Barrett have given you some good ideas, and I also have another suggestion that will work for a science fair project. Remember that when you do a science fair project you want to ask a question that can be answered by doing an experiment. Part of the problem you are having is that your first question doesn’t lend itself to designing an experiment. How about changing the question to “why does lemon juice make a good invisible ink?” To answer, this question, you need to find out what’s in lemon juice, and you will soon find that lemon juice is mostly citric acid, ascorbic acid, sugar (glucose, fructose, and a tiny amount of sucrose), and a few salts like potassium chloride.

http://www.nutritiondata.com/facts/frui ... ces/1938/3

http://en.wikipedia.org/wiki/Lemon

http://www.fineli.fi/food.php?foodid=11557&lang=en

Now to answer your first question, you can ask some more questions:

Does citric acid make invisible ink?
Does glucose/fructose/sucrose make invisible ink?
Does potassium chloride make invisible ink?
Is there something else in the lemon juice that makes invisible ink?

You also know that heat is required for the invisible ink so you could ask a couple of questions about temperature.

Will invisible ink appear when the paper is heated to 100 degrees Centigrade?
Will invisible ink appear when the paper is heated to 150 degrees Centigrade?
(Be careful, paper catches on fire at 233 degrees Centigrade, so stay below this level).

Etc. I’m sure your teacher won’t mind if you turn in extra questions.

Your hypothesis is what you think will happen, based on additional reading that you do.

http://en.wikipedia.org/wiki/Invisible_ink

http://www.kidzworld.com/article/3844-m ... ink-appear

The additional reading might give you ideas for more questions to ask, such as, “is iodine or heat best to develop invisible lemon juice ink? “

One possible experiment would be to make 3 solutions containing the same concentration of 1. citric acid 2. glucose/fructose 3. potassium chloride and test each of these compared to real lemon juice.

I think you are on track for a great science project! Let us know if you need more help.

Donna Hardy