The ax half-life is proper due come the exponential and also quantum nature of radiation decay, which renders it impossible to predict exactly when a solitary atom the radioactive product will disintegrate. The half-life measurement rather relates come statistics, representing the time it takes because that a provided amount that a problem to be reduced by half as a an outcome of decay.

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When one hears the expression “half-life”, many people think of the popular video clip game the the same name, however anyone that has ever read about nuclear power, weapons, storage or rubbish will most likely realize the it is concerned radioactive elements. Scientists measure the half-life the a substance because it speak them about the lot of radiation the a given substance will provide off. Half-life is a fixed continuous for every different substance, permitting experts come accurately suspect the expectancy of a material.

For radiation materials, this can create how lengthy it will take before a material no much longer poses a threat; for other materials, such together carbon-14, half-life can aid in radiometric date (carbon dating), to determine the approximate period of old remains! while this may seem a bit complex for those not familiar with nuclear chemistry, it’s a useful and also versatile ide to fully understand.

What is radiation Decay?

As you may know, atomic aspects can have various isotopes, i m sorry are various versions that an aspect that have actually the same variety of protons, however different number of neutrons consisted of within the nucleus. Thus, the atom mass of these isotopes will be different, together will several of their physical properties, yet their chemical properties are generally the same. Every chemical aspect has one or more isotope, few of which space stable, and others that are unstable. An atom nucleus is considered stable when the pressures holding the protons and also neutrons together space stronger than the forces trying to drive them apart (strong atomic force vs. Electrostatic repulsion).

The simplest example of this is hydrogen, which has actually two stable isotopes—protium (1 proton) and also deuterium (known together “heavy hydrogen”, with 1 proton and also 1 neutron). However, hydrogen likewise has an turbulent naturally arising isotope well-known as tritium, which has 1 proton and also 2 neutrons. The instability that this radioisotopemeans the it desires to break down into a different, much more stable form.


The quantum behavior of individual atoms is impossible to assess, but the actions of a big group of atom is subject to probability, and thus a dependable level of statistics certainty. In atom physics, half-life is a valuable measuring stick because that how easily a radioisotope will certainly undergo radioactive decay, or just how long a steady isotope will remain intact. The is perhaps easiest to know half-life v an example. Let’s take into consideration the half-life that radioisotope nickel-63, i beg your pardon breaks under to copper-63 through beta decay.

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Nickel-63 has a half-life of 100 years, therefore let’s consider a sample of this radioactive facet composed of 1,000,000 atoms. ~ 100 years, roughly 500,000 atoms will have damaged down into copper-63, a steady isotope that will certainly no longer emit radiation or degeneration further, while 500,000 radioactive nickel-63 atoms will certainly remain. Let’s extrapolate this out a little bit further…

100 year – 500,000 nickel-63 atoms

200 year – 250,000 nickel-63 atoms

300 years – 125,000 nickel-63 atoms

400 year – 62,500 nickel-63 atoms

500 years – 31,250 nickel-63 atoms

600 year – 15,625 nickel-63 atoms

When a radiation isotope division down into a steady isotope of “daughter” material, it will not degeneration further or emit any an ext radiation. Thus, over time, the very same of radioactive product will come to be less dangerous, as it will certainly not be create as countless alpha, beta or gamma particles. After 10 half-lives, there will be much less than one-thousandth the the original radioactivity native the sample, and will typically be considered completely harmless.

The price of each material’s radioactive break down remains constant, but every isotope has a different half-life, varying from Hydrogen-7 (1 proton and also 6 neutrons), v a half-life that 2.3×10−23 seconds, all the means up to Tellurium-128 (52 protons and 76 neutrons), which boasts a half-life the 2.2×1024 years—150 trillion times longer than the age of the universe!

A last Word

When you begin looking at things on an atomic or quantum scale, that becomes much more difficult to be an accurate in relation to a single atom. Once looking at a single atom that uranium-235, it is difficult to understand when or if it will certainly undergo radiation decay and also become a single atom the thorium-231. However, when observing a million atoms of uranium-235, the is an exact statistical probability come say that fifty percent of the atoms will have alpha decayed in ~ 703 million years!

While half-life is typically linked with nuclear physics, that is likewise an applicable and useful principle in clinical technology, such together in the pharmacokinetics of details drugs, as well as in the usage of pesticide in plants and also the radiometric carbon date of dinosaur fossils! Half-life calculations room a method to make feeling of the unpredictable quantum realm, and be may be to assess the long-term impact of radioactive materials on both the environment and life on this planet!