1. Radioactive Decay

2. What is Radioactive Decay?
A change in an atom’s nucleus due to the emission of an alpha, beta or gamma radiation.

3. Alpha Particle Two Protons Two Neutrons 42He+2
Easily stopped by a piece of paper

4. Alpha Decay Radioactive decay where an alpha particle is released
The radioactive element loses two protons and two neutrons
Atomic number drops by two
Atomic mass drops by four

5. Example of alpha decay Show how 22688Ra undergoes alpha decay
Atomic mass = = 222
Atomic number = 88-2 = 86
Element with atomic number of 86 = Rn
22688Ra = 42He Rn

6. Beta Particle A fast-moving electron ejected from a nucleus.
Created when a proton splits into a neutron and an electron.
Can be stopped by aluminum foil.
0-1e

7. Beta Decay
Radioactive decay where the nucleus releases a beta particle
The radioactive element converts one neutron into a proton and an electron.
Atomic mass remains the same
Atomic number increases by one

8. Example of Beta Decay Show how 21088Rn undergoes beta decay
Emits a beta particle =0-1e
Atomic mass = stays the same = 210
Atomic number = 88+1 = 89
21088Rn = 21089Ac + 0-1e