pertaining to the bile, to the bile ducts, or to the gallbladder. biliary catheter (biliary decompression catheter) a catheter inserted via a skin incision through the liver and common bile duct into the duodenum.
Not all of the atoms of a radioisotope decay at the same time, but they decay at a rate that is characteristic to the isotope. The rate of decay is a fixed rate called a half-life. The half-life of a radioisotope describes how long it takes for half of the atoms in a given mass to decay.
Some isotopes are radioactive-meaning they radiate energy as they decay to a more stable form, perhaps another element half-life: time required for half of the atoms of an element to decay into stable form. Another example is oxygen, with atomic number of 8 can have 8, 9, or 10 neutrons.