## TRICKY questions about half-Lives...

**Anonymous**

[color=violet]Hi again,

Does anybody know where I can find answers/explanations for this tricky questions?[/color]

[b][color=cyan][size=18]What is the approximate age of dead wood whose level of radioactivity is

mikelyn19 (not verified)| 7 December 2008 - 1:08am## Hi, Does anyone know the

Hi,

Does anyone know the answer to this tricky question?

If you start with 18.0mg of Polonium-210, how many half-lives have occured if you end with 1.125mg?

Anonymous| 21 February 2004 - 9:38pmWe enjoy helping you to understand not simply doing all your home work for you. Maybe you can try the other problems after some info on one of them and get back to us if you need more help.

I'll answer you second question, because it is rather simple. If something has a half life of 10 years that means half of it will be gone in 10 years. Add an other 10 years that means it will halve again. So after 20 years it would of halved 2 times. So that means you have 1/4 of what you started with. Since you started out with 100grams you now have a fourth of it; I'll trust you'll be able to multiply 100 and 1/4 to get your answer.