Science Buddies: "Ask an Expert"

Hi, for my science project, I'm testing polypropylene and how it affects particle occurrence in a cloud chamber. I want to do several trials. Is there a way I can do this by purchasing only one radioactive needle? The needles are expensive that's why.

Hi skanji04,

Your project sounds very interesting!

Firstly, could you explain what you were planning to do with the polypropylene as I could not really find a connection between the cloud chamber and the polypropylene.

Secondly, I do not think you would need a second radioactive needle. The half-life of Pb-210, a common radioactive needle, is 22.3 years, which means it lasts a little more than that said amount of years.

However, please respond to me about the polypropylene, and I will reply to you with a more precise response as quickly as possible.

Thanks and Good Luck,
Shivansh

Hi, I was going to wrap the polypropylene around the radiation source, and record the number of tracks in the cloud chamber. I would then compare it to nothing surrounding the radiation source.

Hey!

Sorry for the late response, but I still do believe that you would not need another needle for a different trial. Lead 210just lasts for such a long time that the amount of decay over the course of your project is negligible. It even says on some packaging that the half-life is around 23 years.

Anyways, half fun and stay safe!