Thrush occurs in children and adults when conditions permit too much growth of a fungus called candida in your mouth. A small amount of this fungus normally lives in your mouth. It is most often kept in check by your immune system and other germs that also live in your mouth. When your immune system is weak or when normal bacteria die, too much of the fungus can grow. You are more likely to get thrush if: You are in poor health.
The rate at which a radioactive isotope decays is measured in half-life. The term half-life is defined as the time it takes for one-half of the atoms of a radioactive material to disintegrate. Half-lives for various radioisotopes can range from a few microseconds to billions of years. See the table below for a list of radioisotopes and each of unique their half-lives. Radioisotope.
This is called the half-life of the radioactive isotope. There are two definitions of half-life, but they mean essentially the same thing. Different radioactive isotopes have different half-lives. For example, the half-life of carbon-14 is 5,715 years, but the half-life of francium-223 is just 20 minutes.