What does the half-life of a radioisotope represent?

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.

The female reproductive cell produced in and released from the ovaries; also called the ovum. Embryo: The developing organism from the time it implants in the uterus up to 8 completed weeks of pregnancy. Fallopian Tube: One of a pair of tubes through which an egg travels from the ovary to the uterus