Why would the alpha particles in the smoke detectors remove electrons from air molecules?
A radioactive source “decays,” or sheds particles and photons from unstable atoms. The particles interact with neutral air molecules flowing through the chamber. The particles remove electrons from air molecules, creating positive ions.
How do smoke detectors use isotopes?
The Am-241 emits alpha particles which ionise the air and allow a current between two electrodes. If smoke enters the detector it absorbs the alpha particles and interrupts the current, setting off the alarm.
Why do smoke alarm not work with beta or gamma?
The main reason that alpha particles are used is that they are strongly ionizing, because they are helium nuclei without any orbiting electrons; they will rip electrons off of any particles that they encounter, whereas gamma rays and beta particles will not.
Why are alpha particles dangerous?
Alpha particles lack the energy to penetrate even the outer layer of skin, so exposure to the outside of the body is not a major concern. The ionizations they cause are very close together – they can release all their energy in a few cells. This results in more severe damage to cells and DNA.
Why is americium named after America?
It decays into neptunium-239 through alpha decay. Americium was the fourth synthetic transuranic element to be discovered and was named after the continent of North America by analogy to its lighter lanthanide homologue, europium, which was named after Europe, its continent of discovery.
What is an interesting fact about americium?
Americium (chemical symbol: Am) Americium is a radioactive, soft, silver-white, heavy metal that is denser than lead and slowly tarnishes in air. With a density of about 13.6 g/cc, it is almost twice as heavy as steel. Americium is a transuranic metal, which means it is located after uranium on the periodic table.
What period is americium in?
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