Page 84 - A Life - my Live - my path

My career - the IRE

Comment: radioactive radiation
There are three types of radiation. Depending on their
structure, they will react more or less quickly with atoms and
particles present on earth (matter, gas) and in the universe.

α (alpha) : is a helium nucleus composed of 2

protons and 2 neutrons. A α (alpha)
particle can travel a few cm in the air. It
doesn’t go through a piece of paper.
-1
-
β (bêta) : is an e electron. Can travel 1 m in air. Is
stopped by a sheet of paper.
Ɣ (gamma) : is a radiation. Can travel several hundred
meters in the air. Is stopped by very dense
materials like lead.

Half-lives can be very different. They can range from
seconds, even milliseconds, to billions of years.
For example, by radioactive decay, we go from uramuim -238 ,
which is found in nature, to uranium -234 , also present in
nature, but in very small quantities. The path is as follows:
• 92 uranium -238 T= 4,5 billion years. α (alpha)
• 90 thorium -234 T= 24,1days. β (bêta)
-
• 91 paladium -234 T= 1,17 minutes. β (bêta)
-
• 92 uranium -234 T= 245.000 years. α (alpha)
If we continue on this path, after almost 100,000 years, we
reach lead -206 which is stable.

72