This instructible shows how to obtain and extract Americium,have fun :)
Step 1: How to Obtain and Extract Americium
Inside inexpensive smoke alarms is a tiny amount of the radioactive element Americium. The isotope used, americium 241, has a half life of 452 years. Since americium 241 decays into the much more stable isotope neptunium 237 (half-life 2.1 million years), the sample in the smoke detector will have a few trillion new neptunium atoms in it every year.