Half-life - Wikipedia
As noted above, in radioactive decay the half-life is the length of time after which there is a 50% chance that an atom will have undergone nuclear decay. It varies depending on the atom type and isotope, …
Half-Life in Radioactive Decay - Science Facts
Jun 10, 2025 · In radioactivity, half-life describes the time it takes for half of the atoms in a sample of a radioactive substance to decay. The half-life is a fixed characteristic of that substance and is …
Half-life | Definition & Facts | Britannica
Dec 3, 2025 · The rate at which a radioactive element decays is expressed in terms of its half-life; i.e., the time required for one-half of any given quantity of the isotope to decay.
31.5: Half-Life and Activity - Physics LibreTexts
Dec 13, 2024 · Intuitively, you would expect the activity of a source to depend on two things: the amount of the radioactive substance present, and its half-life. The greater the number of radioactive nuclei …
Radioactive Half-Life - HyperPhysics
Note that the radioactive half-life is not the same as the average lifetime, the half-life being 0.693 times the average lifetime. The example that causes the most confusion is the decay of the free neutron …
Half-Life – Understanding Radioactive Decay Over Time
Radioactive decay happens at a predictable rate for large groups of atoms, and half-life is the measure that captures this behavior. It tells us how long it takes for half of a sample to decay, allowing us to …
List of radioactive nuclides by half-life - Wikipedia
Twenty-three yoctoseconds is the time needed to traverse a 7- femtometre distance at the speed of light —around the diameter of a large atomic nucleus. The half-life of tellurium-128 is over 160 trillion …
Half-Life | Introductory Chemistry - Lumen Learning
Natural radioactive processes are characterized by a half-life, the time it takes for half of the material to decay radioactively. The amount of material left over after a certain number of half-lives can be easily …
17.5: Natural Radioactivity and Half-Life - Chemistry LibreTexts
The half-life of an isotope is used to describe the rate at which the isotope will decay and give off radiation. Using the half-life, it is possible to predict the amount of radioactive material that will …
D. What is Meant by Half-Life? - Linda Hall Library
3 days ago · The half-life of a radioactive substance is a characteristic constant. It measures the time it takes for a given amount of the substance to become reduced by half as a consequence of decay, …