Chemistry

Radioactivity (continued)


Decay and half life

Radioactivity It is the property of unstable atomic nuclei to emit particles and electromagnetic radiation to become more stable nuclei.

We call this phenomenon radioactive disintegration reaction, transmutation reaction, or decay reaction. The reaction only ends with the formation of stable atoms. Examples:

U -238 decays to Pb-206.

The time it takes for radioactive elements to become stable varies greatly.

Half life - This is the time required for half the isotopes of a sample to disintegrate.

A set of radioactive atoms may be disintegrating right now. Another atom could disintegrate in an hour. Another may disintegrate three months from now. The U-235 is the longest half-life element. It is about 7.04.108 years old.

Example of a Half Life chart: Activity x Time


Example of bismuth decay 210

Effects of radioactivity on organisms

The effects of radioactivity on humans depend on the amount accumulated in the body and the type of radiation. Radioactivity is harmless to human life in small doses, but if the dose is excessive it can cause damage to the nervous system, gastrointestinal tract, bone marrow, etc.

It can often lead to death (within a few days or within ten to forty years, through leukemia or other cancer).

Being in contact with radiation is subtle and not immediately noticeable, as there is no visible pain or injury at the moment of impact. Radiation attacks the cells of the body, causing the atoms that make up the cells to change their structure.

Chemical bonds can be altered, affecting the functioning of cells. This causes, over time, biological consequences for the functioning of the organism as a whole; Some consequences may be perceived in the short term, others in the long term. Sometimes, only the descendants (children, grandchildren) of the person who has undergone any genetic alteration induced by radioactivity will present problems.