Radon-226 Decay: Half-Life of Radium-226

  • Thread starter Thread starter vanceEE
  • Start date Start date
  • Tags Tags
    Decay
Click For Summary

Discussion Overview

The discussion revolves around the decay process of Radium-226, specifically its half-life and the products of its decay. Participants explore the decay chain, the initial decay product, and the subsequent transformations leading to stable lead isotopes.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant states that Radium-226 has a half-life of 1,620 years and decays into lead, questioning whether this is accurate.
  • Another participant asserts that Radium-226 first decays into Radon-222 before eventually leading to lead, providing a decay equation as support.
  • A subsequent post lists the various daughter isotopes of radium, noting their respective half-lives and indicating that most decay products will eventually lead to stable lead isotopes over the long half-life of Radium-226.
  • One participant proposes an equation for the decay process but later acknowledges it as incorrect, suggesting that the decay chain is more complex and involves multiple steps before reaching lead.
  • Another participant expresses uncertainty about the use of barium in a decay equation, prompting clarification and correction to radon in a later response.
  • Participants engage in correcting and refining their earlier claims regarding the decay products and the correct notation for the decay process.

Areas of Agreement / Disagreement

Participants express differing views on the initial decay product of Radium-226, with some asserting it decays to lead directly while others argue it first decays to Radon-222. The discussion reflects multiple competing views and remains unresolved regarding the specifics of the decay process.

Contextual Notes

There are unresolved issues regarding the accuracy of decay equations and the sequence of decay products, as well as the implications of half-lives for the various isotopes involved.

vanceEE
Messages
109
Reaction score
2
"Radium-226 has a half-life of 1,620 years, which means that half of a given sample of radium-226 will decay into lead by the end of 1,620 years. In the next 1,620 years, half of the remaining sample will decay into lead, leaving one-fourth of the original amount of radium-226."(1)

Wouldn't half of the Radium-226 decay into Radon-222 instead of Lead? I am new to this but my previous knowledge of decay from Physics tells me that Radium would would first decay to Radon by the end of 1,620 years which can be described by the equation below:
\stackrel{226}{86}Ra→ \stackrel{222}{84}Rn + \stackrel{4}{2}He

Is (1) a misprint or am I missing the half-life concept?
 
Chemistry news on Phys.org
The main branch daughters of radium are:
radium emanation, half-life 3,8 days
radium A, 3,1 minutes
radium B (lead 214) 27 minutes
radium C 20 minutes
radium C' 165 microseconds
radium D (lead 210) 22,2 years
radium E 5 days
radium F 138,4 days
The final product, stable radium G, is lead 206.
So all non-lead daughters of radium have a combined half-life of under 148 days. Over the 1600 year half-life of radium, almost all that has decayed into radium emanation has gone on to lead.
 
I think it should be more like

^{226}_{\phantom{0}88}Ra \rightarrow {}^{222}_{\phantom{0}86}Ba + ^{4}_{2}He

Edit: this is wrong, idiotic mistake. See below.

What they mean is most likely that there is a long decay chain which ends with Pb. If most steps are faster, that's effectively as if the Ra was decaying into Pb with a given half life.
 
Last edited:
Borek said:
I think it should be more like

^{226}_{\phantom{0}88}Ra \rightarrow {}^{222}_{\phantom{0}86}Ba + ^{4}_{2}He

Are you really sure about Barium?
 
Sigh, I copy pasted nice LaTeX from another post - and I corrected atomic masses, but got distracted and left Ba from the original code :redface:

^{226}_{\phantom{0}88}Ra \rightarrow {}^{222}_{\phantom{0}86}Rn + ^{4}_{2}He
 
:-)
How about
\mathrm{^{226}_{\phantom{0}88}Ra \rightarrow {}^{222}_{\phantom{0}86}Rn + ^{4}_{2}He}?
 

Similar threads

Undergrad Understanding Branching Fraction: Ra-226 Example
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Decay series and their energies
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Radon Gas & Radium 226: Health Effects & Decay
  • · Replies 5 ·
Replies
5
Views
6K
Graduate Where Do the Two Electrons Go During Alpha Decay?
  • · Replies 6 ·
Replies
6
Views
5K
What is the Conversion Rate from Curie to Becquerel?
  • · Replies 8 ·
Replies
8
Views
2K
Graduate Calculation of alpha particles from 226-Ra decay
  • · Replies 3 ·
Replies
3
Views
3K
Intense physics question, mix of radioactive decay and electromagnetism
  • · Replies 4 ·
Replies
4
Views
2K
Why is radon in houses still dangerous?
  • · Replies 4 ·
Replies
4
Views
2K
Why Were Some Alpha Particles Detected in Radium-226 Decay but Not Others?
  • · Replies 2 ·
Replies
2
Views
4K
Radioactivity & Specific Heat Capacity Question
  • · Replies 3 ·
Replies
3
Views
4K