2.4: Half-lives - Chemistry LibreTexts
The half-life of a reaction (\(t_{1/2}\)), is the amount of time needed for a reactant concentration to decrease by half compared to its initial concentration. Its application is used in chemistry and medicine to predict the concentration of a substance over time.
Half-life - Wikipedia
In a chemical reaction, the half-life of a species is the time it takes for the concentration of that substance to fall to half of its initial value. In a first-order reaction the half-life of the reactant is ln (2)/λ, where λ (also denoted as k) is the reaction rate constant.
Half-life | Definition & Facts | Britannica - Encyclopedia Britannica
Half-life, in radioactivity, the interval of time required for one-half of the atomic nuclei of a radioactive sample to decay, or, equivalently, the time interval required for the number of disintegrations per second of a radioactive material to decrease by one-half.
5.7: Calculating Half-Life - Chemistry LibreTexts
Jun 26, 2023 · A useful concept is half-life (symbol is \(t_{1/2}\)), which is the time required for half of the starting material to change or decay. Half-lives can be calculated from measurements on the change in mass of a nuclide and the time it takes to occur.
Radioactive Half-Life: Definition, Equation, Graph, & Table
Sep 4, 2024 · Radioactive half-life describes the time it takes for half of the atoms in a sample of a radioactive substance to decay. The half-life of a radioactive substance is a fixed characteristic of that substance and is independent of the amount of material present.
11.2: Half-Life - Chemistry LibreTexts
Aug 13, 2022 · The half-life of a radioactive isotope is the amount of time it takes for one-half of the 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.
Half-Life Definition and Examples in Chemistry, Biology, Physics
Jun 18, 2024 · It represents the time for half of a given quantity of a substance to transform into something else. Examples of processes that transform with a half-life include radioactive decay, a chemical reaction, or the elimination of a substance from a biological system.
Half-Life - ChemTalk
What is a Half-Life? A half-life (t 1/2) is the time it takes half the concentration of a sample to decay. For example, if the starting concentration of a sample is 1M, then the half-life will be the time it takes for the concentration of the sample to decay to 0.5M.
Half-Life | Introductory Chemistry - Lumen Learning
Half-Life | Introductory Chemistry. Learning Objectives. Define half-life. Determine the amount of radioactive substance remaining after a given number of half-lives. Whether or not a given isotope is radioactive is a characteristic of that particular isotope.
Half-Lives and Radioactive Decay Kinetics - Chemistry LibreTexts
Jan 30, 2023 · The half-life of a reaction is the time required for the reactant concentration to decrease to one-half its initial value. The half-life of a first-order reaction is a constant that is related to the rate constant for the reaction: t 1 /2 = 0.693/ k .
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