1. Radioactivity and types of Radiation
Contents:
Discovery of Radiation
Types of Decay/Radiation
Whiteboard

2. Antoine Henri Becquerel
Discovery of Radioactivity
U salts cloud film on protected plates
Ionized air
Could be deflected by B field (unlike X rays)
Discovered radioactive decay (demo radioactive rocks)
Antoine Henri Becquerel
Parent Nucleus
(Before)
Daughter Nucleus
(After)
Radiation
Decay is a spontaneous nuclear reaction
TOC

3. Types of decay and radiation
Decay Type
 (Alpha)
- (Beta-)
+ (Beta+)
 (Gamma)
What it is
2p2n (He nuc)
(4 cm air)
e- (electron)
(Thin Al foil, 1-3 m air)
e+ (positron)
High energy Photon
( nm)
(some thickness of lead)
Effect on Parent
A - 4, Z - 2
A - 0, Z + 1 (Conservation of charge)
(neutron to proton)
A - 0, Z - 1
(proton to neutron)
A - 0, Z - 0
Parent loses mass
TOC

5. Whiteboards:
Decay Products
1 | 2 | 3 | 4 | 5
TOC

6. 21082Pb ______ +   = 2p2n, 4 nucleons, 2 protons 210 - 4 = 206
= 80 Hg (Mercury) W
206/80 Hg

7. 14561Pm ______ +   = 2p2n, 4 nucleons, 2 protons 145 - 4 = 141
= 59 Pr (Praseodymium) W
141/59 Praseodymium

8. 158O ______ + + + = Proton turns to a neutron
Nucleons remain unchanged
Z = = 7 (Nitrogen) W
15/7 N

9. 4019K ______ + + + = Proton turns to a neutron
Nucleons remain unchanged
Z = = 18 Ar W
40/18 Ar

10. 4019K ______ + - - = Neutron turns to proton
Nucleons remain unchanged
Z = = 20 Ca W
40/20 Ca

11. 6027Co ______ + - - = Neutron turns to proton
Nucleons remain unchanged
Z = = 28 Ni W
60/28 Ni

12. 22286Rn ______ +   = High energy photon Nucleons remain unchanged
Protons remain unchanged W
222/86 Rn

13. Decay series:
U238>Th234+
Th234>Pa234+
Pa234>U234+
U234>Th230+
Th230>Ra226+
Ra226>Rn222+
Rn222>Po218+
Uh - then it gets a little complicated
Eventually the product is stable
Online Nuclides