What is a simple definition of half-life?
Definition of half-life 1 : the time required for half of something to undergo a process: such as. a : the time required for half of the atoms of a radioactive substance to become disintegrated.
What is the meaning of half-life in biology?
The time required for a biological system, such as that of a human, to eliminate, by natural processes, half of the amount of a substance (such as a radioactive material) that has entered it.
What are the 2 definitions of half-life?
Half-life is the time it takes for half of the unstable nuclei in a sample to decay or for the activity of the sample to halve or for the count rate to halve.
What does half-life mean in anatomy?
Definition of half-life the time required for one half the atoms of a given amount of a radioactive substance to disintegrate. Also called biological half-life . Pharmacology. the time required for the activity of a substance taken into the body to lose one half its initial effectiveness.
What does half-life mean radiation?
The time required for half the atoms of a particular radioisotope to decay into another isotope. A specific half-life is a characteristic property of each radioisotope. Measured half-lives range from millionths of a second to billions of years, depending on the stability of the nucleus.
What is the relationship between radioactivity and half-life?
The longer the half-life of a nucleus, the lower the radioactive activity. A nucleus with a half-life that is a million times greater than another will be a million times less radioactive. A ‘half-life’ is defined as the amount of time taken for the number of nuclei present in a sample at a given time to exactly halve.
Why is half-life so important?
Knowing about half-lives is important because it enables you to determine when a sample of radioactive material is safe to handle. The rule is that a sample is safe when its radioactivity has dropped below detection limits. And that occurs at 10 half-lives.
What is the half-life story about?
Half-Life, stylized as HλLF-LIFE, is a science fiction first-person shooter developed and published by Valve. The player takes the perspective of the scientist Gordon Freeman who struggles to escape an underground research facility after a failed experiment causes a massive alien invasion through a dimensional rift.
Why do we use half-life?
Half-life (symbol t1⁄2) is the time required for a quantity to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable atoms survive.