What is a half-life in simple terms?
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.
How is half-life used in science?
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.
How long is a half-life in science?
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.
What is a half-life in chemistry?
An interesting and useful aspect of radioactive decay is half-life, which is the amount of time it takes for one-half of a radioactive isotope to decay. The half-life of a specific radioactive isotope is constant; it is unaffected by conditions and is independent of the initial amount of that isotope.
Why is half-life important?
Understanding the concept of half-life is useful for determining excretion rates as well as steady-state concentrations for any specific drug. Different drugs have different half-lives; however, they all follow this rule: after one half-life has passed, 50% of the initial drug amount is removed from the body.
Why do we measure half-life?
Scientists measure the half-life of a substance because it tells them about the amount of radiation that a given substance will give off. Half-life is a fixed constant for every different substance, allowing experts to accurately predict the lifespan of a material.
Why is it called half-life?
A half-life is the time taken for something to halve its quantity. The term is most often used in the context of radioactive decay, which occurs when unstable atomic particles lose energy. Twenty-nine elements are known to be capable of undergoing this process.
Does water have a half-life?
Water. The biological half-life of water in a human is about 7 to 14 days. It can be altered by behavior.
What is the longest half-life?
The half-life of xenon-124 — that is, the average time required for a group of xenon-124 atoms to diminish by half — is about 18 sextillion years (1.8 x 10^22 years), roughly 1 trillion times the current age of the universe. This marks the single longest half-life ever directly measured in a lab, Wittweg added.
What happens after a half-life?
So if a radioactive element has a half life of one hour, this means that half of it will decay in one hour. After another hour, half of the remaining material will decay.
What is the definition of a half-life quizlet?
Half life definition. the average time it takes for the number of nuclei in a radioactive isotope sample to halve. the radioactivity of a sample always. decreases over time.