Download 13. nuclear

 In radioactivity, the nucleus of an unstable isotope or
element decays spontaneously and gives off rays and
particles. Table O lists the decay particles and rays.
MASS
CHARGE
 The alpha particle is a positively charged particle. The alpha
particle will be attracted to the negative side of the magnet
(red) because the red is the negative end.
 The gamma particle has no charge, so it will not be attracted
to either side.
 The beta particle is negatively charged particle. The beta
particle will be attracted to the positive end of the magnet.
Question: Draw the correct
transmutation for the
radioactive isotope 220Fr.
What element does it
transmutate into?
220
4 He + X
Fr

87
2
220Fr
spontaneously decays and
gives off alpha particles
 When the nucleus of an element is first bombarded
with high energy particles!!
THEN it decays and changes into a new element!
**Artificial Transmutations are easy to spot!!
If you see an atom AND one of the high energy
particles on left side of arrow combining to make a
new element on the right side of arrow, then it is an
artificial transmutation!!
In other words:
Artificial Transmutations  Have TWO reactants
Natural Transmutations  Have ONE reactant
 One atom absorbs a neutron and splits
into two or more pieces, giving off a
tremendous amount of energy.
235
92U
+
1
0n
→ 23692U
141
56Ba
+ 9236Kr + 310n + energy
 Fission occurs in nuclear reactors and the atomic bomb
(chain reaction)
FISSION is Division
 When the two light nuclei unite to form a heavier nucleus.
2
1H
+
2
1H
→
4
2He
 This is the type of energy that exists on the SUN, and the
HYDROGEN BOMB.
 Fusion requires extremely high temperature and pressure in
order for it to occur.
Fusion creates more energy than fission
FUSION is a union
NOTHING CAN
CHANGE
THE
HALF LIFE OF A
RADIOISOTOPE!
1. Tracers: Used to trace the path of chemical reactions in
living organisms (Carbon-14).
2. Medical Uses: Used in medical diagnosis and treatment of
diseases! Isotopes with very short half-lives
are used for this because they decay very quickly!
Examples:



Technetium -99 : Used to pinpoint brain tumors!
Iodine -131: Used to diagnose and treat thyroid disorders!
Radium & Cobalt-60: Used in cancer treatment!
3. Food Storage: Radiation kills bacteria, yeast, and mold in
food, therefore permitting food to be stored
for longer periods of time!
4. Radioactive Dating:

Geologic Dating: Based on half-life! Certain radioactive
elements occur naturally in ROCK and so they are used
to find the AGE of certain rocks!


Examples: URANIUM-238 & LEAD-206
Dating Living Materials: Can help determine the age of
wood, bone, animal skin, etc…

Example: CARBON -14 & CARBON-12
5. Nuclear Power: Nuclear reactors are used for ELECTRICAL
ENERGY!!
6. Indiustrial Measurement: Used to measure the thickness of
certain metals.

Example: Alpha, Beta, and Gamma particles!
4. Radioactive Dating:

Geologic Dating: Based on half-life! Certain radioactive
elements occur naturally in ROCK and so they are used
to find the AGE of certain rocks!


Examples: URANIUM-238 & LEAD-206
Dating Living Materials: Can help determine the age of
wood, bone, animal skin, etc…

Example: CARBON -14 & CARBON-12
5. Nuclear Power: Nuclear reactors are used for ELECTRICAL
ENERGY!!
6. Indiustrial Measurement: Used to measure the thickness of
certain metals.

Example: Alpha, Beta, and Gamma particles!