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

Nuclear physics
Nucleus  · Nucleons (p, n)  · Nuclear matter  · Nuclear force  · Nuclear structure  · Nuclear reaction
Models of the nucleus Liquid drop · Nuclear shell model · Interacting boson model · Ab initio
Nuclides' classification Isotopes – equal Z Isobars – equal A Isotones – equal N Isodiaphers – equal N − Z      Isomers – equal all the above Mirror nuclei – Z ↔ N Stable · Magic · Even/odd · Halo
Nuclear stability Binding energy · p–n ratio · Drip line · Island of stability · Valley of stability
Radioactive decay Alpha α · Beta β (2β, β+) · K/L capture · Isomeric (Gamma γ · Internal conversion) · Spontaneous fission · Cluster decay · Neutron emission · Proton emission Decay energy · Decay chain · Decay product · Radiogenic nuclide
Nuclear fission Spontaneous · Products (pair breaking) · Photofission
Capturing processes electron · neutron (s · r) · proton (p · rp)
High energy processes Spallation (by cosmic ray) · Photodisintegration
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High energy nuclear physics Quark–gluon plasma  · RHIC  · LHC
Scientists Alvarez · Becquerel · Bethe · A.Bohr · N.Bohr · Chadwick · Cockcroft · Ir.Curie · Fr.Curie · Pi.Curie · Skłodowska-Curie · Davisson · Fermi · Hahn · Jensen · Lawrence · Mayer · Meitner · Oliphant · Oppenheimer · Proca · Purcell · Rabi · Rutherford · Soddy · Strassmann · Szilárd · Teller · Thomson · Walton · Wigner
v t e

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

U238⟶Th234⏟daughter of 238U⟶Pa234m⏟granddaughter of 238U⟶⋯⟶Pb206⏞decay products of 238Udisplaystyle ce ^238U->overbrace underbrace ce ^234Th _ce daughter~of~^238Uce ->underbrace ce ^234!mPa _ce granddaughter~of~^238Uce ->cdots ->^206Pb ^ce decay~products~of~^238U

In this example:

• 
  ²³⁴Th, ^234mPa,…,²⁰⁶Pb are the decay products of ²³⁸U.


• 
  ²³⁴Th is the daughter of the parent ²³⁸U.


• 
  ^234mPa (234 metastable) is the granddaughter of ²³⁸U.

These might also be referred to as the daughter products of ²³⁸U.^[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 or bismuth. Bismuth itself decays to thallium, but the decay is so slow as to be practically negligible.

In many cases, individual members of the decay chain are as radioactive as the parent, but far smaller in volume/mass. Thus, although uranium is not dangerously radioactive when pure, some pieces of naturally occurring pitchblende are quite dangerous owing to their radium-226 content, which is soluble and not a ceramic like the parent. Similarly, thorium gas mantles are very slightly radioactive when new, but become more radioactive after only a few months of storage as the daughters of ²³²Th build up.

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.

See also

• Decay chain

References