# Decay product

﻿
Decay product
The decay chain from lead-212 down to lead-208, showing the intermediate decay products.

In nuclear physics, a decay product (also known as a daughter product, daughter isotope or daughter nuclide) is the remaining nuclide left over from radioactive decay. Radioactive decay often involves a sequence of steps (decay chain). For example, U-238 decays to Th-234 which decays to Pa-234 which decays, and so on, to Pb-206 (which is stable):

$\mbox{U-238} \rightarrow \overbrace{ \underbrace{\mbox{Th-234}}_{\mbox{daughter of U-238}} \rightarrow \underbrace{\mbox{Pa-234m}}_{\mbox{granddaughter of U-238}} \rightarrow \ldots \rightarrow \mbox{Pb-206} }^{\begin{array}{c} \mbox{decay products of U-238} \end{array}}$

In this example:

• Th-234, Pa-234m,…,Pb-206 are the decay products of U-238.
• Th-234 is the daughter of the parent U-238.
• Pa-234m (234 metastable) is the granddaughter of U-238.

These might also be referred to as the daughter products of U-238.[1]

Decay products are important in understanding radioactive decay and the management of radioactive waste.

For elements above lead in atomic number, the decay chain typically ends with an isotope of lead.

In many cases members of the decay chain are far more radioactive than the original nuclide. Thus, although uranium is not dangerously radioactive when pure, some pieces of naturally-occurring pitchblende are quite dangerous owing to their radium content. Similarly, thorium gas mantles are very slightly radioactive when new, but become far more radioactive after only a few months of storage.

Although it cannot be predicted whether any given atom of a radioactive substance will decay at any given time, the decay products of a radioactive substance are extremely predictable. Because of this, decay products are important to scientists in many fields who need to know the quantity or type of the parent product. Such studies are done to measure pollution levels (in and around nuclear facilities) and for other matters.

## References

1. ^ Glossary of Volume 7 (Depleted Uranium — authors: Naomi H. Harley, Ernest C. Foulkes, Lee H. Hilborne, Arlene Hudson, and C. Ross Anthony) of A review of the scientific literature as it pertains to gulf war illnesses.

Wikimedia Foundation. 2010.

### Look at other dictionaries:

• decay product — skilimo produktas statusas T sritis fizika atitikmenys: angl. decay product; disintegration product vok. Zerfallsprodukt, n rus. продукт распада, m pranc. produit de désintégration, m …   Fizikos terminų žodynas

• decay product — a nuclide, which may be stable or radioactive, resulting from the radioactive disintegration of a radionuclide, being formed either directly or as the result of successive transformations in a radioactive series. Called also daughter …   Medical dictionary

• Decay chain — In nuclear science, the decay chain refers to the radioactive decay of different discrete radioactive decay products as a chained series of transformations. Most radioactive elements do not decay directly to a stable state, but rather undergo a… …   Wikipedia

• decay — I. verb Etymology: Middle English, from Anglo French decaïr, from Late Latin decadere to fall, sink, from Latin de + cadere to fall more at chance Date: 15th century intransitive verb 1. to decline from a sound or prosperous condition 2. to… …   New Collegiate Dictionary

• decay — 1. Destruction of an organic substance by slow combustion or gradual oxidation. 2. SYN: putrefaction. 3. To deteriorate; to undergo slow combustion or putrefaction. 4. In dentistry, caries. 5. In psychology, loss of informat …   Medical dictionary

• decay — /dəˈkeɪ/ (say duh kay) verb (i) 1. to fall away from a state of excellence, prosperity, health, etc.; deteriorate; decline. 2. to become decomposed; rot. 3. Physics a. (of a radioactive substance) to transform into a daughter product. b. (of an… …   Australian English dictionary

• Exponential decay — A quantity undergoing exponential decay. Larger decay constants make the quantity vanish much more rapidly. This plot shows decay for decay constants of 25, 5, 1, 1/5, and 1/25 for x from 0 to 5. A quantity is said to be subject to exponential… …   Wikipedia

• disintegration product — skilimo produktas statusas T sritis fizika atitikmenys: angl. decay product; disintegration product vok. Zerfallsprodukt, n rus. продукт распада, m pranc. produit de désintégration, m …   Fizikos terminų žodynas

• daughter product — /ˈdɔtə prɒdʌkt/ (say dawtuh produkt) noun radioactive decay product …   Australian English dictionary

• Fission product — Fission products are the atomic fragments left after a large nucleus fissions. Typically, a large nucleus like Uranium fissions by splitting into two smaller nuclei, along with a few neutrons and a large release of energy in the form of heat… …   Wikipedia

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.