SlideShare a Scribd company logo
1 of 24
Download to read offline
Radioactivity and Nuclear decay
Madhava B Mallia
Radiopharmaceuticals Division
Radiochemistry and Isotope Group
BHABHA ATOMIC RESEARCH CENTRE
Trombay, Mumbai - 400 085, INDIA
• Atom!!!
• Radioactivity and nuclear decay process
• Kinetics of radioactive decay
• Decay constant and half-life
• Units of radioactivity
Overview
2
Atom: “Smallest indivisible particle of matter…”
3
ATOM Mass No. A = Number of protons + number of neutrons
Atomic No. Z = Number of protons
Radioactivity
Radioactivity is a phenomenon of spontaneous emission of
radiation by unstable nuclei
Henri Becquerel
4
Radioactivity: Story of unstable nucleus
5
Florescence: Atomic phenomenon Radioactivity: Nuclear phenomenon
6
Radioactive decay  Loose energy  Attain stability
Particles Electromagnetic
radiation
Types of radioactive decay
7
Alpha α Helium nucleus
Beta β-/β+ Electron/Positron
Gamma  Electromagnetic
Radiation
Auger Electron
223
88Ra  219
86Rn + 4
2He 223
88Ra87Fr219
86Rn
α Decay
8
β- Decay
9
131
53I  131
54Xe + β- 131
54Xe131
53I
10
18
9F  18
8O + β+ 18
9F18
8O
β+ Decay
 Emission
• Transition of nucleus from excited state to ground state
11
99mTc  99Tc + gamma
N/P ratio and nuclear stability in layman’s terms
12
N/P ratio = Neutron/Proton ratio
Carbon-11 Carbon-12 Carbon-13 Carbon-14
N 5 6 7 8
P 6 6 6 6
N/P 0.83 1 1.16 1.33
Status Radioactive Stable Stable Radioactive
Mode of decay Positron (β+) - - Beta (β-)
13
Carbon-11
N 5
P 6
N/P 0.83
Status Radioactive
Boron-11
N 6
P 5
N/P 1.2
Status Stable
Carbon-14
N 8
P 6
N/P 1.33
Status Radioactive
Nitrogen-14
N 7
P 7
N/P 1
Status Stable
Attaining stability through radioactive decay
Characteristics of radioisotopes
• Half-life
• Type of radiation
• Energy of radiation
14
Actenium-225 (half-life – 10 days)
Alpha - 5.79 MeV (8.6%); 5.73 MeV (10.0%); 5.79 MeV (18.1%); 5.83 MeV (51.6%)
Gamma – 12 keV (21.3%)
Lutetium-177 (half-life – 6.9 days)
Beta (max) - 0.18 MeV (12.3%); 0.49 (78.7%)
Gamma - 112.95 keV (6.4%); 208.36 keV (11.0%)
Technetium-99m (half-life – 6 hours)
Gamma – 140 keV
Kinetics of radioactive decay
Radioactive decay follows first order kinetics
15
A B
-dN/dt = N
‘N’

N = N0 e-t
-dN/dt  N
Where ‘’ is called decay constant
Decoding Decay Constant
16
N = N0 e-t
Number Number Unit less quantity
Unit of ‘’ = inverse of unit of time
Unit of ‘’ = S-1 (Second inverse)
Decay constant  Probability of nuclear decay per second
17
Activity
N = N0 e-t
Activity, A = N
 x x 
N = N0 e-t
A = A0 e-t
Activity = Number of disintegrations happening per second
Radioactivity and its units
• SI unit – Bq (Bequerels)
• 1 Bq = 1 dps (disintegrations per second)
• 1 Curie – 3.7 x 1010 dps (Bq) – Disintegrations in 1 gram of 226Ra
• 1 millicurie – 37 MBq
• 1 microcurie – 37 kBq
18
Plot of A Vs time
19
Half-life of a radioisotope
Half-life (t1/2) – Time taken to reduce the activity of a radioactive sample to half the
initial value
A = A0 e-t
At t = t1/2 , A = A0/2 x e-t1/2
t1/2 = 0.693/λ
Half-life is a constant for a given radioisotope
20
Determination of half-life graphical method
21
Can you alter half-life?
22
When will a single nucleus of a radioactive atom
decay?
23
One half life One half life
Finally
What is my fate?
THANK YOU...24

More Related Content

What's hot

Atoms and radioactivity
Atoms and radioactivityAtoms and radioactivity
Atoms and radioactivityAsuquo Asuquo
 
Chapter 22.2 : Radioactive Decay
Chapter 22.2 : Radioactive DecayChapter 22.2 : Radioactive Decay
Chapter 22.2 : Radioactive DecayChris Foltz
 
Radioisotopes : Properties
Radioisotopes : PropertiesRadioisotopes : Properties
Radioisotopes : PropertiesAman Verma
 
Radiobiology2
Radiobiology2Radiobiology2
Radiobiology2zedan
 
Radioactive decay, kinetics and equilibrium
Radioactive decay, kinetics and equilibriumRadioactive decay, kinetics and equilibrium
Radioactive decay, kinetics and equilibriumBiji Saro
 
Radioactivity: physics form 5.
Radioactivity: physics form 5.Radioactivity: physics form 5.
Radioactivity: physics form 5.Ramli Rem
 
Half life of radioactive material
Half life of radioactive materialHalf life of radioactive material
Half life of radioactive materialMirzaMusmanBaig
 
Radiopharmaceuticals final
Radiopharmaceuticals finalRadiopharmaceuticals final
Radiopharmaceuticals finalAkshita Singh
 
Learning more about radioactivity by AREVA - 2005 publication
Learning more about radioactivity by AREVA - 2005 publicationLearning more about radioactivity by AREVA - 2005 publication
Learning more about radioactivity by AREVA - 2005 publicationAREVA
 
Radioactivity
RadioactivityRadioactivity
Radioactivitywilsone
 
Physics 23 radioactivity
Physics 23   radioactivityPhysics 23   radioactivity
Physics 23 radioactivityNurul Fadhilah
 
AS Level Physics' Radioactivity Presentation
AS Level Physics' Radioactivity PresentationAS Level Physics' Radioactivity Presentation
AS Level Physics' Radioactivity PresentationAkmal Cikmat
 
Discovery of radioactivity
Discovery of   radioactivityDiscovery of   radioactivity
Discovery of radioactivityyash8894
 

What's hot (20)

Radioactivity
RadioactivityRadioactivity
Radioactivity
 
Radioactivity
RadioactivityRadioactivity
Radioactivity
 
Atoms and radioactivity
Atoms and radioactivityAtoms and radioactivity
Atoms and radioactivity
 
Chapter 22.2 : Radioactive Decay
Chapter 22.2 : Radioactive DecayChapter 22.2 : Radioactive Decay
Chapter 22.2 : Radioactive Decay
 
Radioisotopes : Properties
Radioisotopes : PropertiesRadioisotopes : Properties
Radioisotopes : Properties
 
Radiobiology2
Radiobiology2Radiobiology2
Radiobiology2
 
Introduction to radioactivity
Introduction to radioactivityIntroduction to radioactivity
Introduction to radioactivity
 
Radioactive decay, kinetics and equilibrium
Radioactive decay, kinetics and equilibriumRadioactive decay, kinetics and equilibrium
Radioactive decay, kinetics and equilibrium
 
Radioactivity: physics form 5.
Radioactivity: physics form 5.Radioactivity: physics form 5.
Radioactivity: physics form 5.
 
Half life of radioactive material
Half life of radioactive materialHalf life of radioactive material
Half life of radioactive material
 
Radiopharmaceuticals final
Radiopharmaceuticals finalRadiopharmaceuticals final
Radiopharmaceuticals final
 
Learning more about radioactivity by AREVA - 2005 publication
Learning more about radioactivity by AREVA - 2005 publicationLearning more about radioactivity by AREVA - 2005 publication
Learning more about radioactivity by AREVA - 2005 publication
 
Radioactivity
RadioactivityRadioactivity
Radioactivity
 
Radioactivity
RadioactivityRadioactivity
Radioactivity
 
Physics 23 radioactivity
Physics 23   radioactivityPhysics 23   radioactivity
Physics 23 radioactivity
 
Radioactivity
RadioactivityRadioactivity
Radioactivity
 
AS Level Physics' Radioactivity Presentation
AS Level Physics' Radioactivity PresentationAS Level Physics' Radioactivity Presentation
AS Level Physics' Radioactivity Presentation
 
Radioactivity
RadioactivityRadioactivity
Radioactivity
 
Discovery of radioactivity
Discovery of   radioactivityDiscovery of   radioactivity
Discovery of radioactivity
 
Unit 17 Radioactive Decay
Unit 17 Radioactive DecayUnit 17 Radioactive Decay
Unit 17 Radioactive Decay
 

Similar to Radioactivity and nuclear decay

RADIOACTIVITY for Nuclear Chemistry Course.ppt
RADIOACTIVITY for Nuclear Chemistry Course.pptRADIOACTIVITY for Nuclear Chemistry Course.ppt
RADIOACTIVITY for Nuclear Chemistry Course.pptDrSafiurRahman
 
Basic concept of radiation, radioactivity, radiation dose
Basic concept of radiation,  radioactivity, radiation doseBasic concept of radiation,  radioactivity, radiation dose
Basic concept of radiation, radioactivity, radiation dosemahbubul hassan
 
Ch18 z7e nuclear
Ch18 z7e nuclearCh18 z7e nuclear
Ch18 z7e nuclearblachman
 
Chapter_23_Nuclear_Chemistry.ppt
Chapter_23_Nuclear_Chemistry.pptChapter_23_Nuclear_Chemistry.ppt
Chapter_23_Nuclear_Chemistry.pptJiesel1
 
Nuclear Chemistry Powerpoint 2003
Nuclear Chemistry Powerpoint   2003Nuclear Chemistry Powerpoint   2003
Nuclear Chemistry Powerpoint 2003jeksespina
 
Nuclear Chemistry Powerpoint 2003
Nuclear Chemistry Powerpoint   2003Nuclear Chemistry Powerpoint   2003
Nuclear Chemistry Powerpoint 2003Jelor Gallego
 
Ch18z7enuclear 110115233000-phpapp01
Ch18z7enuclear 110115233000-phpapp01Ch18z7enuclear 110115233000-phpapp01
Ch18z7enuclear 110115233000-phpapp01Cleophas Rwemera
 
5. radioactive decay nuclear medicine
5. radioactive decay nuclear medicine5. radioactive decay nuclear medicine
5. radioactive decay nuclear medicineCHERUDUGASE
 
F5 c5 radioactivity
F5 c5 radioactivityF5 c5 radioactivity
F5 c5 radioactivityCammry Anna
 
Nuclear Chemistry Powerpoint
Nuclear Chemistry PowerpointNuclear Chemistry Powerpoint
Nuclear Chemistry Powerpointjeksespina
 
Chapter 23 nuclear_chemistry
Chapter 23 nuclear_chemistryChapter 23 nuclear_chemistry
Chapter 23 nuclear_chemistrySirod Judin
 
Radiation detector and measurement tech.pdf
Radiation detector and measurement tech.pdfRadiation detector and measurement tech.pdf
Radiation detector and measurement tech.pdfssuserb523ad
 
Radioisotope production and application
Radioisotope production and applicationRadioisotope production and application
Radioisotope production and applicationmadhavmb
 
"Counting Atoms for Astrophysics"
"Counting Atoms for Astrophysics""Counting Atoms for Astrophysics"
"Counting Atoms for Astrophysics"Chad Orzel
 

Similar to Radioactivity and nuclear decay (20)

RADIOACTIVITY for Nuclear Chemistry Course.ppt
RADIOACTIVITY for Nuclear Chemistry Course.pptRADIOACTIVITY for Nuclear Chemistry Course.ppt
RADIOACTIVITY for Nuclear Chemistry Course.ppt
 
Basic concept of radiation, radioactivity, radiation dose
Basic concept of radiation,  radioactivity, radiation doseBasic concept of radiation,  radioactivity, radiation dose
Basic concept of radiation, radioactivity, radiation dose
 
Ch18 z7e nuclear
Ch18 z7e nuclearCh18 z7e nuclear
Ch18 z7e nuclear
 
Nuclear chemistry
Nuclear chemistryNuclear chemistry
Nuclear chemistry
 
Chapter_23_Nuclear_Chemistry.ppt
Chapter_23_Nuclear_Chemistry.pptChapter_23_Nuclear_Chemistry.ppt
Chapter_23_Nuclear_Chemistry.ppt
 
Nuclear Chemistry Powerpoint 2003
Nuclear Chemistry Powerpoint   2003Nuclear Chemistry Powerpoint   2003
Nuclear Chemistry Powerpoint 2003
 
Nuclear Chemistry Powerpoint 2003
Nuclear Chemistry Powerpoint   2003Nuclear Chemistry Powerpoint   2003
Nuclear Chemistry Powerpoint 2003
 
Nuclear chemistry
Nuclear chemistryNuclear chemistry
Nuclear chemistry
 
Ch18z7enuclear 110115233000-phpapp01
Ch18z7enuclear 110115233000-phpapp01Ch18z7enuclear 110115233000-phpapp01
Ch18z7enuclear 110115233000-phpapp01
 
5. radioactive decay nuclear medicine
5. radioactive decay nuclear medicine5. radioactive decay nuclear medicine
5. radioactive decay nuclear medicine
 
F5 c5 radioactivity
F5 c5 radioactivityF5 c5 radioactivity
F5 c5 radioactivity
 
Nuclear Chemistry Powerpoint
Nuclear Chemistry PowerpointNuclear Chemistry Powerpoint
Nuclear Chemistry Powerpoint
 
Chapter 23 nuclear_chemistry
Chapter 23 nuclear_chemistryChapter 23 nuclear_chemistry
Chapter 23 nuclear_chemistry
 
Radiation detector and measurement tech.pdf
Radiation detector and measurement tech.pdfRadiation detector and measurement tech.pdf
Radiation detector and measurement tech.pdf
 
Phy 310 chapter 8
Phy 310   chapter 8Phy 310   chapter 8
Phy 310 chapter 8
 
Radioisotope production and application
Radioisotope production and applicationRadioisotope production and application
Radioisotope production and application
 
"Counting Atoms for Astrophysics"
"Counting Atoms for Astrophysics""Counting Atoms for Astrophysics"
"Counting Atoms for Astrophysics"
 
Radiation detectors
Radiation detectorsRadiation detectors
Radiation detectors
 
Introduction to
Introduction to Introduction to
Introduction to
 
Radiopharmaceutical
Radiopharmaceutical Radiopharmaceutical
Radiopharmaceutical
 

More from madhavmb

Radiation for cancer detection and cure
Radiation for cancer detection and cureRadiation for cancer detection and cure
Radiation for cancer detection and curemadhavmb
 
Chameleon reactions
Chameleon reactionsChameleon reactions
Chameleon reactionsmadhavmb
 
Understanding nuclear medicine
Understanding nuclear medicineUnderstanding nuclear medicine
Understanding nuclear medicinemadhavmb
 
Radioisotope applications in health care sdcp-2019-for share
Radioisotope applications in health care sdcp-2019-for shareRadioisotope applications in health care sdcp-2019-for share
Radioisotope applications in health care sdcp-2019-for sharemadhavmb
 
Kit based sirt agents
Kit based sirt agentsKit based sirt agents
Kit based sirt agentsmadhavmb
 
Brief history and current status of sirt agents
Brief history and current status of sirt agentsBrief history and current status of sirt agents
Brief history and current status of sirt agentsmadhavmb
 
Ligands for radiopharmaceuticals application
Ligands for radiopharmaceuticals applicationLigands for radiopharmaceuticals application
Ligands for radiopharmaceuticals applicationmadhavmb
 
Fibers to fabric: For class 6
Fibers to fabric: For class 6Fibers to fabric: For class 6
Fibers to fabric: For class 6madhavmb
 
Changes in nature: For class 6
Changes in nature: For class 6Changes in nature: For class 6
Changes in nature: For class 6madhavmb
 
Separation of substances: For class 6
Separation of substances: For class 6Separation of substances: For class 6
Separation of substances: For class 6madhavmb
 
Understanding p h and ph indicators: for class 6
Understanding p h and ph indicators: for class 6Understanding p h and ph indicators: for class 6
Understanding p h and ph indicators: for class 6madhavmb
 

More from madhavmb (11)

Radiation for cancer detection and cure
Radiation for cancer detection and cureRadiation for cancer detection and cure
Radiation for cancer detection and cure
 
Chameleon reactions
Chameleon reactionsChameleon reactions
Chameleon reactions
 
Understanding nuclear medicine
Understanding nuclear medicineUnderstanding nuclear medicine
Understanding nuclear medicine
 
Radioisotope applications in health care sdcp-2019-for share
Radioisotope applications in health care sdcp-2019-for shareRadioisotope applications in health care sdcp-2019-for share
Radioisotope applications in health care sdcp-2019-for share
 
Kit based sirt agents
Kit based sirt agentsKit based sirt agents
Kit based sirt agents
 
Brief history and current status of sirt agents
Brief history and current status of sirt agentsBrief history and current status of sirt agents
Brief history and current status of sirt agents
 
Ligands for radiopharmaceuticals application
Ligands for radiopharmaceuticals applicationLigands for radiopharmaceuticals application
Ligands for radiopharmaceuticals application
 
Fibers to fabric: For class 6
Fibers to fabric: For class 6Fibers to fabric: For class 6
Fibers to fabric: For class 6
 
Changes in nature: For class 6
Changes in nature: For class 6Changes in nature: For class 6
Changes in nature: For class 6
 
Separation of substances: For class 6
Separation of substances: For class 6Separation of substances: For class 6
Separation of substances: For class 6
 
Understanding p h and ph indicators: for class 6
Understanding p h and ph indicators: for class 6Understanding p h and ph indicators: for class 6
Understanding p h and ph indicators: for class 6
 

Recently uploaded

Grant Readiness 101 TechSoup and Remy Consulting
Grant Readiness 101 TechSoup and Remy ConsultingGrant Readiness 101 TechSoup and Remy Consulting
Grant Readiness 101 TechSoup and Remy ConsultingTechSoup
 
social pharmacy d-pharm 1st year by Pragati K. Mahajan
social pharmacy d-pharm 1st year by Pragati K. Mahajansocial pharmacy d-pharm 1st year by Pragati K. Mahajan
social pharmacy d-pharm 1st year by Pragati K. Mahajanpragatimahajan3
 
Accessible design: Minimum effort, maximum impact
Accessible design: Minimum effort, maximum impactAccessible design: Minimum effort, maximum impact
Accessible design: Minimum effort, maximum impactdawncurless
 
Web & Social Media Analytics Previous Year Question Paper.pdf
Web & Social Media Analytics Previous Year Question Paper.pdfWeb & Social Media Analytics Previous Year Question Paper.pdf
Web & Social Media Analytics Previous Year Question Paper.pdfJayanti Pande
 
IGNOU MSCCFT and PGDCFT Exam Question Pattern: MCFT003 Counselling and Family...
IGNOU MSCCFT and PGDCFT Exam Question Pattern: MCFT003 Counselling and Family...IGNOU MSCCFT and PGDCFT Exam Question Pattern: MCFT003 Counselling and Family...
IGNOU MSCCFT and PGDCFT Exam Question Pattern: MCFT003 Counselling and Family...PsychoTech Services
 
Nutritional Needs Presentation - HLTH 104
Nutritional Needs Presentation - HLTH 104Nutritional Needs Presentation - HLTH 104
Nutritional Needs Presentation - HLTH 104misteraugie
 
Sports & Fitness Value Added Course FY..
Sports & Fitness Value Added Course FY..Sports & Fitness Value Added Course FY..
Sports & Fitness Value Added Course FY..Disha Kariya
 
Q4-W6-Restating Informational Text Grade 3
Q4-W6-Restating Informational Text Grade 3Q4-W6-Restating Informational Text Grade 3
Q4-W6-Restating Informational Text Grade 3JemimahLaneBuaron
 
Introduction to Nonprofit Accounting: The Basics
Introduction to Nonprofit Accounting: The BasicsIntroduction to Nonprofit Accounting: The Basics
Introduction to Nonprofit Accounting: The BasicsTechSoup
 
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...christianmathematics
 
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...fonyou31
 
Student login on Anyboli platform.helpin
Student login on Anyboli platform.helpinStudent login on Anyboli platform.helpin
Student login on Anyboli platform.helpinRaunakKeshri1
 
Measures of Dispersion and Variability: Range, QD, AD and SD
Measures of Dispersion and Variability: Range, QD, AD and SDMeasures of Dispersion and Variability: Range, QD, AD and SD
Measures of Dispersion and Variability: Range, QD, AD and SDThiyagu K
 
fourth grading exam for kindergarten in writing
fourth grading exam for kindergarten in writingfourth grading exam for kindergarten in writing
fourth grading exam for kindergarten in writingTeacherCyreneCayanan
 
Advanced Views - Calendar View in Odoo 17
Advanced Views - Calendar View in Odoo 17Advanced Views - Calendar View in Odoo 17
Advanced Views - Calendar View in Odoo 17Celine George
 
Disha NEET Physics Guide for classes 11 and 12.pdf
Disha NEET Physics Guide for classes 11 and 12.pdfDisha NEET Physics Guide for classes 11 and 12.pdf
Disha NEET Physics Guide for classes 11 and 12.pdfchloefrazer622
 
Unit-IV- Pharma. Marketing Channels.pptx
Unit-IV- Pharma. Marketing Channels.pptxUnit-IV- Pharma. Marketing Channels.pptx
Unit-IV- Pharma. Marketing Channels.pptxVishalSingh1417
 
A Critique of the Proposed National Education Policy Reform
A Critique of the Proposed National Education Policy ReformA Critique of the Proposed National Education Policy Reform
A Critique of the Proposed National Education Policy ReformChameera Dedduwage
 
General AI for Medical Educators April 2024
General AI for Medical Educators April 2024General AI for Medical Educators April 2024
General AI for Medical Educators April 2024Janet Corral
 

Recently uploaded (20)

Grant Readiness 101 TechSoup and Remy Consulting
Grant Readiness 101 TechSoup and Remy ConsultingGrant Readiness 101 TechSoup and Remy Consulting
Grant Readiness 101 TechSoup and Remy Consulting
 
social pharmacy d-pharm 1st year by Pragati K. Mahajan
social pharmacy d-pharm 1st year by Pragati K. Mahajansocial pharmacy d-pharm 1st year by Pragati K. Mahajan
social pharmacy d-pharm 1st year by Pragati K. Mahajan
 
Accessible design: Minimum effort, maximum impact
Accessible design: Minimum effort, maximum impactAccessible design: Minimum effort, maximum impact
Accessible design: Minimum effort, maximum impact
 
Web & Social Media Analytics Previous Year Question Paper.pdf
Web & Social Media Analytics Previous Year Question Paper.pdfWeb & Social Media Analytics Previous Year Question Paper.pdf
Web & Social Media Analytics Previous Year Question Paper.pdf
 
IGNOU MSCCFT and PGDCFT Exam Question Pattern: MCFT003 Counselling and Family...
IGNOU MSCCFT and PGDCFT Exam Question Pattern: MCFT003 Counselling and Family...IGNOU MSCCFT and PGDCFT Exam Question Pattern: MCFT003 Counselling and Family...
IGNOU MSCCFT and PGDCFT Exam Question Pattern: MCFT003 Counselling and Family...
 
Nutritional Needs Presentation - HLTH 104
Nutritional Needs Presentation - HLTH 104Nutritional Needs Presentation - HLTH 104
Nutritional Needs Presentation - HLTH 104
 
Sports & Fitness Value Added Course FY..
Sports & Fitness Value Added Course FY..Sports & Fitness Value Added Course FY..
Sports & Fitness Value Added Course FY..
 
Q4-W6-Restating Informational Text Grade 3
Q4-W6-Restating Informational Text Grade 3Q4-W6-Restating Informational Text Grade 3
Q4-W6-Restating Informational Text Grade 3
 
Mattingly "AI & Prompt Design: The Basics of Prompt Design"
Mattingly "AI & Prompt Design: The Basics of Prompt Design"Mattingly "AI & Prompt Design: The Basics of Prompt Design"
Mattingly "AI & Prompt Design: The Basics of Prompt Design"
 
Introduction to Nonprofit Accounting: The Basics
Introduction to Nonprofit Accounting: The BasicsIntroduction to Nonprofit Accounting: The Basics
Introduction to Nonprofit Accounting: The Basics
 
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
Explore beautiful and ugly buildings. Mathematics helps us create beautiful d...
 
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
Ecosystem Interactions Class Discussion Presentation in Blue Green Lined Styl...
 
Student login on Anyboli platform.helpin
Student login on Anyboli platform.helpinStudent login on Anyboli platform.helpin
Student login on Anyboli platform.helpin
 
Measures of Dispersion and Variability: Range, QD, AD and SD
Measures of Dispersion and Variability: Range, QD, AD and SDMeasures of Dispersion and Variability: Range, QD, AD and SD
Measures of Dispersion and Variability: Range, QD, AD and SD
 
fourth grading exam for kindergarten in writing
fourth grading exam for kindergarten in writingfourth grading exam for kindergarten in writing
fourth grading exam for kindergarten in writing
 
Advanced Views - Calendar View in Odoo 17
Advanced Views - Calendar View in Odoo 17Advanced Views - Calendar View in Odoo 17
Advanced Views - Calendar View in Odoo 17
 
Disha NEET Physics Guide for classes 11 and 12.pdf
Disha NEET Physics Guide for classes 11 and 12.pdfDisha NEET Physics Guide for classes 11 and 12.pdf
Disha NEET Physics Guide for classes 11 and 12.pdf
 
Unit-IV- Pharma. Marketing Channels.pptx
Unit-IV- Pharma. Marketing Channels.pptxUnit-IV- Pharma. Marketing Channels.pptx
Unit-IV- Pharma. Marketing Channels.pptx
 
A Critique of the Proposed National Education Policy Reform
A Critique of the Proposed National Education Policy ReformA Critique of the Proposed National Education Policy Reform
A Critique of the Proposed National Education Policy Reform
 
General AI for Medical Educators April 2024
General AI for Medical Educators April 2024General AI for Medical Educators April 2024
General AI for Medical Educators April 2024
 

Radioactivity and nuclear decay

  • 1. Radioactivity and Nuclear decay Madhava B Mallia Radiopharmaceuticals Division Radiochemistry and Isotope Group BHABHA ATOMIC RESEARCH CENTRE Trombay, Mumbai - 400 085, INDIA
  • 2. • Atom!!! • Radioactivity and nuclear decay process • Kinetics of radioactive decay • Decay constant and half-life • Units of radioactivity Overview 2
  • 3. Atom: “Smallest indivisible particle of matter…” 3 ATOM Mass No. A = Number of protons + number of neutrons Atomic No. Z = Number of protons
  • 4. Radioactivity Radioactivity is a phenomenon of spontaneous emission of radiation by unstable nuclei Henri Becquerel 4 Radioactivity: Story of unstable nucleus
  • 5. 5 Florescence: Atomic phenomenon Radioactivity: Nuclear phenomenon
  • 6. 6 Radioactive decay  Loose energy  Attain stability Particles Electromagnetic radiation
  • 7. Types of radioactive decay 7 Alpha α Helium nucleus Beta β-/β+ Electron/Positron Gamma  Electromagnetic Radiation Auger Electron
  • 8. 223 88Ra  219 86Rn + 4 2He 223 88Ra87Fr219 86Rn α Decay 8
  • 9. β- Decay 9 131 53I  131 54Xe + β- 131 54Xe131 53I
  • 10. 10 18 9F  18 8O + β+ 18 9F18 8O β+ Decay
  • 11.  Emission • Transition of nucleus from excited state to ground state 11 99mTc  99Tc + gamma
  • 12. N/P ratio and nuclear stability in layman’s terms 12 N/P ratio = Neutron/Proton ratio Carbon-11 Carbon-12 Carbon-13 Carbon-14 N 5 6 7 8 P 6 6 6 6 N/P 0.83 1 1.16 1.33 Status Radioactive Stable Stable Radioactive Mode of decay Positron (β+) - - Beta (β-)
  • 13. 13 Carbon-11 N 5 P 6 N/P 0.83 Status Radioactive Boron-11 N 6 P 5 N/P 1.2 Status Stable Carbon-14 N 8 P 6 N/P 1.33 Status Radioactive Nitrogen-14 N 7 P 7 N/P 1 Status Stable Attaining stability through radioactive decay
  • 14. Characteristics of radioisotopes • Half-life • Type of radiation • Energy of radiation 14 Actenium-225 (half-life – 10 days) Alpha - 5.79 MeV (8.6%); 5.73 MeV (10.0%); 5.79 MeV (18.1%); 5.83 MeV (51.6%) Gamma – 12 keV (21.3%) Lutetium-177 (half-life – 6.9 days) Beta (max) - 0.18 MeV (12.3%); 0.49 (78.7%) Gamma - 112.95 keV (6.4%); 208.36 keV (11.0%) Technetium-99m (half-life – 6 hours) Gamma – 140 keV
  • 15. Kinetics of radioactive decay Radioactive decay follows first order kinetics 15 A B -dN/dt = N ‘N’  N = N0 e-t -dN/dt  N Where ‘’ is called decay constant
  • 16. Decoding Decay Constant 16 N = N0 e-t Number Number Unit less quantity Unit of ‘’ = inverse of unit of time Unit of ‘’ = S-1 (Second inverse) Decay constant  Probability of nuclear decay per second
  • 17. 17 Activity N = N0 e-t Activity, A = N  x x  N = N0 e-t A = A0 e-t Activity = Number of disintegrations happening per second
  • 18. Radioactivity and its units • SI unit – Bq (Bequerels) • 1 Bq = 1 dps (disintegrations per second) • 1 Curie – 3.7 x 1010 dps (Bq) – Disintegrations in 1 gram of 226Ra • 1 millicurie – 37 MBq • 1 microcurie – 37 kBq 18
  • 19. Plot of A Vs time 19
  • 20. Half-life of a radioisotope Half-life (t1/2) – Time taken to reduce the activity of a radioactive sample to half the initial value A = A0 e-t At t = t1/2 , A = A0/2 x e-t1/2 t1/2 = 0.693/λ Half-life is a constant for a given radioisotope 20
  • 21. Determination of half-life graphical method 21
  • 22. Can you alter half-life? 22
  • 23. When will a single nucleus of a radioactive atom decay? 23 One half life One half life Finally What is my fate?