1. Definition: Form of ionizing radiation resulting
from changes in the NUCLEUS of atoms.

2.  Definition:
◦ Change in an atom’s nucleus due to emission of alpha,
beta, or gamma radiation.

3. http://www.teachers.tv/themes/ttv3/microsites/iop/index.html

4. © 2003 John Wiley and Sons Publishers

5. © 2003 John Wiley and Sons Publishers

6.  alpha particle
emission
◦ loss of a helium
nucleus.

8.  1) Alpha Decay of Radon – 226
 2) Alpha Decay of Uranium - 238

9. Problem Pu-239 (plutonium
239) loses an alpha particle
(He nucleus). Write the
nuclear reaction

10. Loss of a β-particle (a high energy electron)
β
0
−1
e
0
−1or
I
131
53 Xe
131
54→
+ e
0
−1

11.  beta emission
◦ A neutron splits into a proton and electron which
is spit out as a β particle.

12.  1) Beta Decay of
Potassium – 40
 2) Beta Decay of Bismuth - 214

13. Loss of a γ-ray (high-energy radiation that almost
always accompanies the loss of a nuclear
particle)
γ
0
0

14. Positron: particle with the same mass as an
electron, but opposite charge.
e
0
1
C
11
6 →
B
11
5 + e
0
1
Positron emission of carbon-11

15.  The decay of by positron emission.

16.  Electron capture: Occurs when the nucleus of an
atom draws in a surrounding electron, combining
with a proton to form a neutron.
 Electron Capture of rubidium-81:
p
1
1 + e
0
−1 →
n
1
0

17.  The decay of by electron capture.

18. 18
Nuclide Half-Life Area of Body
I–131 8.1 days Thyroid
Fe–59 45.1 days Red Blood Cells
Sr–87 2.8 hours Bones
Tc–99 6.0 hours Heart
Na–24 14.8 hours Circulatory System

20. http://www.thephysicsteacher.ie/radioactivityapplets.html