Final answer:
The half-life of a radioactive isotope is the time required for half of the atoms in a sample to decay. This property is a measure of an isotope's radioactivity and remains constant regardless of the starting number of atoms or the external conditions. Isotopes with shorter half-lives decay more rapidly than those with longer half-lives.
Step-by-step explanation:
The Concept of Half-life in Radioactive Isotopes
The term you are referring to is not the "radiation period" but the half-life of a radioactive isotope. The half-life (T1/2) of a radioactive substance is defined as the time required for half of the atoms in a sample of a radioisotope to decay. This property is a key indicator of the radioactivity of an isotope, representing the number of decays that happen per unit time. Isotopes with shorter half-lives decay more rapidly and thus have a greater number of radioactive decays per unit time compared to isotopes with longer half-lives. The half-life is independent of the initial quantity and is not affected by external conditions.
For example, if a radioactive isotope has a half-life of 1 hour, this means that after 1 hour, half of the original atoms have decayed. After another hour, half of the remaining atoms will have decayed, and so forth. This sequential decay continues with each half-life period passing, resulting in an exponential decrease in the number of radioactive atoms present.
It's important to note that the half-life varies among different isotopes; some can be extremely long, like Uranium-234 with a half-life of 245,000 years, while others can be extremely short, such as some isotopes with half-lives in milliseconds. The half-life helps us understand how long a radioactive isotope will remain active or how long it should be stored before its radiation level diminishes to a safer level.