[hudsy]

How is chemical bonding used in Am and making smoke detectors?

[jdurg]

Americium is used in smoke detectors NOT because of its chemical properties but because of the fact that it emits a constant source of alpha particles and incredibly weak gamma rays.  As a result, its radiation is easily contained as alpha particles can't move through more than a few inches of air, and the gamma rays are so weak that if you are a meter away from the source you receive virtually no radiation from it.  Inside the detector, a matrix containg less than 35kBq of Am-241 in the form of AmO2 emits a constant source of alpha particles which ionizes the air in a specific chamber.  If a good deal of heat and/or smoke enters this chamber, it alters the conductivity of the air which causes an alarm to go off.