First, hello. this is my first post. I am a mature student studying science.
I'm sure this is very basic, but if anyone can help I'd be very glad.
This is radioactive decay related. I need a formula to calculate from the half-life of a source material, when will there be only 1/9 of it left. The amount of time. I'm rearranging ln and λ but getting a bit confused.
Please let me know if you need more information.
Many thanks.
Jack