1. NUCLEAR CHEMISTRY e e  Types of Radioactivity (TABLE O).
Radioactivity results from an unstable ratio
Between mass# and protons in the nucleus
NUCLEAR CHEMISTRY
Types of Radioactivity (TABLE O).
Alpha particle: 
Beta Particle: -
Gamma Ray: 
positron: + 4 He 2 =
Helium
nuclei
High energy (x-rays)
High power
High penetration
FAST e -1 e +1
Same as a
-1 charge
Same as a
+1 charge with no mass
Low penetrating power
Low Energy (E)
Medium E
medium penetrater
Mass number 4 He 2
NATURAL RADIOACTIVITY: occurs in nature
(DECAY) happens spontaneously
1 thing breaks into more than one thing
1  2
All types listed on TABLE N and O
Atomic number
# protons
How do we separate out and identify the types of radioactivity---use a electric or magnetic field -
Radioactive
Source
(particle) 
, +

2.  Fr He At Au Hg e Ca e K Fr n Fr Fr Fr Emits a beta (-) particle
NUCLEAR CHEMISTRY CNT’D
TYPES OF PARTICLE DECAY(natural radioactivity)
Emits an alpha () particle
Particle Accelerators:
Alpha Fr
220 87 He 4 2 At
216 85
Can be linear or circular
Work by alternating magnetic fields to accelerate the particle
Particle MUST have a CHARGE or it will not be accelerated
Neutron and Gamma particle DON’T WORK +
Mass number(left) = mass number (right) 220 =
Atomic # (left) = atomic # (right) 87 =
Emits a beta (-) particle
Beta Au
198 79 Hg
198 80 + e -1
Emits a positron (+) particle
Positron Ca 37 20 e +1 K 37 19 +
Emits a neutron (n) particle
Neutron Fr
220 87 n 1 Fr
219 87 +
(note: atomic # didn’t change)
Emits a gamma () particle
Gamma
(this does not stabilize nucleus) Fr
220 87  Fr
220 87 +

3. Half life:
10 kg bunny
Amount of time for half of the radioactive sample to turn into (decay) something stable
3 days
5 kg bunny
Decay rate
Listed on table N
Nothing affects ½ life!!!
3 more days
3 more days
3 more days
2.5 kg bunny
remains
0.625 kg bunny
remains
1.25 kg bunny
remains
How much time did it take for ½ the bunny to decay?
How many ½ lives do we see here?

4. Li n H He H H He He He U n H He U n n Pu U n Ba Kr H H He n n
ARTIFICIAL TRANSMUTATIONS: Man Made
Particle is accelerated and shot into the nucleus of another particle (man does this)
NOT SPONTANEOUS
Two particles on left side of arrow yield 2 or more new particles on right side of arrow
E = mc2
Any mass “lost” is converted to Energy
Nuclear
Disintegration
FISSION
FUSION
ARTIFICIALLY MADE!!
Big atom(heavy)hit by a particle
COMBINES (fuses) nuclei
Smaller nuclei combine to make bigger atoms
Breaks the nucleus of big atom up into smaller atoms (2 or more) and more particles Li 6 3 n 1 H 3 1 He 4 2 + + H 1 H 1 He 2 +
Usually see the following: He 4 2
Always small masses
Always a change in ID of
element: He 4 2 + U
238 92 n 1 + H 1 He 4 2 U
235 92 n 1 + +
Atomic # wise…
3+0 = 1 + 2
Li changed to He
ALL produce Large amounts of ENERGY n 1 + Pu
239
CHAIN REACTION!!
NEED HIGH TEMP/HIGH Pres. U
235 92 n 1 Ba
139 56 Kr 95 36 H 2 1 H 3 1 He 4 2 n 1
Masses add up too.
6+1=3+4 + + + + n 1
+ENERGY
These guys can
Go on and hit more
Uranium
+ 3
SUN DOES FUSION

5. USES AND PROBLEMS WITH RADIOACTIVITY
RADIOACTIVE WASTE
Medicine;
Used to diagnose and treat cancers
Need SHORT ½ life and cleared
fast from the body
Most common:
I-131: for thyroid
Tc-99: detect brain cancer
Co-60: cancer treatment
Radium: cancer treatment
Disposed carefully –transported securely
Often buried (extensively long ½ life means buried for remainder of our lives and those to come)
Has to be secure
Only becomes stable when it becomes a gas Rn(g) N2(g)
RADIOACTIVE DATING
TRACERS:
Geological USE
Used to trace metabolic functions and mechanisms in organic processes
Uses ½ life to calculate age
Use to determine age of object, fossil, rock, preserved skeletal remains, etc.
Common ones: 3H, 32P, 14C
Used to detect cracks in airplanes
60Co
Inorganic (rock) U-235
Organic dating C-14