1. Nuclear Chemistry
An Energetic Concept

2. Who did What Wilhelm Roentgen Laboratory generated phosphorescence
X-rays

3. Who did What Henri Becquerel Inherited U salts (pitchblende)
Natural phosphorescence
Discovered spontaneous
phosphorescence

4. Who did What Marie & Pierre Curie
Studied Becquerel phosphorescence and named it
Discovered Po, Ra

5. X Isotope Review A Z A—mass number Z—atomic number
A – Z = number of neutrons

6. So, What is Radiation? Instability due to n:p+ Radioisotopes
Goal is stability

7. So, What is Radiation?

8. Types of Radiation Rutherford Electric field effect on radioactivity
Alpha
Beta
Gamma

9. Types of Radiation

10. Types of Radiation Alpha () Same as a He-4 nucleus A decreases by 4
Z decreases by 2

11. Types of Radiation Alpha Not very penetrating
Stopped by a sheet of paper
Very ionizing

12. Types of Radiation Beta () Same as an electron A remains the same
Z increases by 1 e

13. Types of Radiation Beta More penetrating than 
Stopped by a thin sheet of metal
Less ionizing than 

14. Types of Radiation Gamma () Pure energy Usually accompanies  and 
More penetrating than  and 
Somewhat blocked by several inches of Pb or several feet of concrete
Less ionizing than  and 

15. F  O + e Types of Radiation Positron (+) Same mass as 
Opposite charge of 
F  O + e 18 9 8 +1

16. K + e  Ar Types of Radiation Electron capture
The opposite of  emission
A remains the same
Z decreases by 1
K + e  Ar 40 19 18 -1

17. Decay Series Continued radiation until stable
Fr-221 undergoes the following decay series: ,,,,,
Fr  At + He
221 87
217 85 4 2
At  Bi + He
217 85
213 83 4 2
Bi  Tl He
213 83
209 81 4 2
Tl  Pb e
209 81 82 -1
Pb  Bi e
209 82 83 -1
Bi  Tl He
209 83
205 81 4 2

18. Rate of Radioactive Decay
Half-Life
t½ = 0.693/k
k = rate law constant
First-order Kinetics
lnN = –kt + lnNo
N…amount after elapsed time
t = elapsed time
No = amount originally

19. Units of Radioactive Decay
curie (Ci)
1 Ci = 3.7 x 1010 disintegrations per second
~activity of 1 g of Ra-226
becquerel (Bq)
SI unit
1 Bq = 1 dis/s…37 GBq = 1 Ci

20. Units of Radiation exposure
sievert (Sv)
Dose absorbed by specific tissue
Replaced röntgen equivalent to man (rem)
1 Sv…nausea
2-5 Sv…hair loss, hemorrhage
3 Sv…death in 50% of people in 30 days
>6 Sv…unlikely survival
Typical background exposure is
2.4 mSv/year

21. Rate of Radioactive Decay
The half-life of F-18 is 2 hours. If you receive a dose of 200 mCi at 8:00 AM, how long will it take for 10 mCi to remain in your body? At what time will you have 10 mCi in you?
Solve for the value of k
Plug into the linear equation and solve for t

22. Rate of Radioactive Decay
2 h = 0.693/k…
k = h-1
ln(10 mCi) = –( h-1)(t) + ln(200 mCi)
ln(10 mCi) – ln(200 mCi) = –( h-1)(t)
– 2.996= –( h-1)(t)
8.65 h = t
at 4:39 PM, you will have 10 mCi in you

23. Radioactive Dating
C-14 is a beta emitter with a half-life of 5730 years
Used to determine the age of carbon- based substances