Science Buddies: "Ask an Expert"

Hello,
I would like to ask how you would write a question and hypothesis for this particular science project. For the question, I wrote "what is the effect of radioactive decay on the predictive power of dating the half-life of rocks?". So, how would you write the hypothesis? Would the hypothesis have to somehow relate with how you think that radioactive decay will help predict the age of rocks? Or would it be what I wrote, which is predicting the amount of time units needed for half the parent isotopes in a rock to decay into daughter isotopes (I predicted 4 time units). I would really appreciate t if you could possibly tell me if my hypothesis was okay, or if I need to change it.

Thank you very much for the help,
HelpWithScience

Hi,

I think your second hypothesis is the correct one. If you look at the Procedure section of the project:https://www.sciencebuddies.org/science- ... #procedure

you will see that it tells you to predict the half-life from the known probability (1 chance in 6) of a 'radioactive decay' and compare that to the half-life that you calculate from the graph of fraction remaining vs time (rolls of the dice):

Graph the Decay Curve and Determine the Half-Life Time

In this part of the science project, you will create a graph of the decay curve of your isotope and use your curve to determine the half-life time of your isotope. Remember, the half-life time of an isotope is the time it takes for half of the initial amount of isotopes to decay. You will then compare the half-life time you obtained using your data to the predicted half-life time using probability. How close will your half-life time be to the calculated one?

So, your hypothesis is the predicted half-life and you test it by rolling the dice until all the isotope atoms have decayed, then graph the result and find the number of rolls of the dice to get to a fraction of 0.5--one half decayed.

I think my reasoning is correct, but other experts please weigh in here if you have experience with this kind of project!

If you have more questions, do let us know.

Sybee

Hi,
Thanks for the reply! I would also like to ask if my question actually fits the experiment or if I should change it (question was stated on the previous post).

Thanks again,
HelpWithScience

Since this project does not involve experiments with actual radioactivity then I don't think your question has relevance here. It is a valid question, however, and you can do some online reading and cite references if you want to discuss it.

Projects like this are more in the nature of demonstrations of principles than experiments to test a hypothesis. The rolling of the dice represents the randomness of radioactive decay and graphing the results gives you a visual representation of how an isotope's half-life is determined.

If you have more questions I will be happy to try and answer them.

Sybee

Hello,
Thanks once again! Do you possibly have any recommendations for the question? If not, can you possibly give some ideas? Thank you for everything you are doing to help me, I really appreciate it.

Thank you very much,
HelpWithScience

I'm not sure I am understanding what you mean. Are you wanting to ask some question that you can test using the dice model of radioactive decay?

The only aspect of radioactive decay that I can think of that you could model with the dice would be the lack of effect of temperature on the rate of decay. I guess you could put the dice in the freezer and then do the same 'experiment' with them that you did with room-temperature dice. This proves nothing. It just mimics what you already know about radioactive isotopes--that the rate of decay is not affected by the temperature of the isotope atoms.

Please let me know if this is not what you are after. Post again with a little more details about what your project requires and I will try to help.

Sybee

I am doing science fair and this was the experiment I chose to do for it. In science fair, we need to come up with a question that is in the form of "what is the effect of _______ on _________?" So I was wondering if you could give me some ideas for the science fair question. My original question was on the first post.

Thanks,
HelpWithScience

Hi,
how about ''what is the effect of time on a rock?

alyssia

In my last post I gave you one possible question. Maybe you didn't understand. The question was: What is the effect of temperature on radioactive decay?

I explained how you can 'test' this using the dice model, but it is not an experiment. It is a model demonstration of radioactive decay. The two things are scientifically very different and you need to understand that difference.

Read the Scibuddies guide on how to make a science fair question: https://www.sciencebuddies.org/science- ... ctquestion

And also, read the information on what a scientific hypothesis is and how to write one: https://www.sciencebuddies.org/science- ... hypothesis

Please post again if you don't understand these concepts because they are important to an understanding of what science is and is not.

Sybee

Hi,
How does this experiment relate with real life? Who could the results of this experiment help?
Thanks,
HelpWithScience

Radioisotopes are used in medicine, industry, archaeoloogy and geology for many purposes. Here's one example:

http://science.howstuffworks.com/dictio ... g-info.htm

The questions are part of your science report and YOU have to answer them in your own words. The dice demonstration was just to teach you about radioactive decay. Your project was not about dice, it was about radioisotopes. What are they, what are their physical characteristics and how are they put to use in science. All this information is online.