What happens during one half-life of a radioactive isotope?

In the field of radioactivity, the half-life is usually defined as the time required by an unstable radioactive isotope to disintegrate half of its initial composition. For different radioactive isotope elements, this value of half-life is different.

For example, the half-life of uranium-238 is approximately 4.5 billion years and the half-life of Carbon-14 is nearly 5700 years.

During the time of one half-life of a radioactive isotope, half of the parent atoms are disintegrated and forms a comparatively stable daughter isotope. This means that half of the initial concentration of the unstable isotope is reduced.