- Radioisotopes are unstable isotopes that decay and emit radiation. They can be naturally occurring or artificially produced by bombarding nuclides with particles. - Radioisotopes have many medical uses like treating cancer and thyroid disorders. Iodine-131 and cobalt-60 are used for radiation therapy. Tracers like sodium-24 help study blood circulation. - They also have applications in agriculture like using phosphorus-32 to study plant metabolism, and in archaeology by using carbon-14 for radiocarbon dating to estimate the age of organic artifacts. - Additional uses include detecting leaks in underground pipes by tracing radioisotopes in water, measuring steel thickness, and studying the wearing rate of engines.

1. -NUR ARINA BINTI AHMAD SIDI-
-13202-
-413/513-
-T. NoRAZILA-

2. 5.3
UNDERSTANDING THE
USES OF RADIOISOTOPES

3. O Isotopes are atoms of an element which
have the same proton number but
different nucleon number.
O Some isotopes are referred to as
'stable' and others as 'unstable' or
'radioactive'.

4. O Radioisotopes are unstable isotopes
which decay and give out radioactive
emissions.
O Radioisotopes are naturally occuring or
artificially produced.
O Artificial radioisotopes can be produced
when certain nuclides are bombarded by
high energy particles.

5. O Example :
When a nucleus of magnesium-24
is bombarded by a neutron,
sodium-24 can be produced.

6. MEDICAL AGRICULTURE
ARCHEOLOGY INDUSTRIES

7. MEDICAL
O Nuclear medicine is a branch of medicine that uses
radiation to provide information about the function
of the specific organs of a patient or to treat
disease :
 The rays from radium is used in the treatment of skin
diseases.
 Radiation from Co60 ( - rays) is used to diagnose and
treat thyroid disorders.
 Radio iodine (I131) is used to diagnose and treat
thyroid disorders.
 Radio phosphorus (P32) is used in the treatment of
leukaemia and tumours.
 Radio sodium (Na24) in the form NaCl is used to study
circulation of blood.

8. NUCLEAR MEDICINE
O Click here to watch more..
• http://www.youtube.com/watch?v=H1
nxAxozOYI

9. AGRICULTURE
O Radioactive phosphorus (P32) is used in the
study of metabolism of plants.
O Radioactive sulphur (S35) helps to study
advantages and disadvantages of
fungicides.
O Pests and insects on crops can be killed by
radiations
O Yield of crops like carrot, root, apples,
grapes can be increased by irradiation with
radioisotopes.

10. Uses of radioisotopes in
agriculture
Phosphorus

11. ARCHEOLOGY
O In archaeology radioisotope carbon-14 is
used to study and estimate the age of
ancient artifacts. This method is named as
the radiocarbon dating.
O Radiocarbon dating can be used to estimate
the age of organic materials, such as wood
and leather, up to about 58,000 to 62,000
years.

12. Radiocarbon Dating
Example:
A piece of wood found in a cave of an archaeology
site has a carbon-14 activity 25% of the activity
from a live plant. Estimate the age of the wood.
[Half-life of carbon-14 = 5730 years]
Answer:
100% → 50% → 25%
Carbon-14 take 2 half-life to decay from 100% to
25%, hence the age of the wood
= 2(5730)
= 11460 years

13. INDUSTRIES
O Monitoring thickness of steel/paper
sheet
O Leaks in pipes may be traced by
introducing a small quantity of
radioisotopes into the fluid in the pipe.
O It is also used to detect the cracks in
the welding, casting etc.
O Measuring the wearing rate of engine

14. Monitoring thickness of
steel or paper sheets
Monitor by
computer-
Computer will
make a proper
adjusment
according to the
thickness
High reading will be
recorded if the thickness is
less than normal
Radioactive detector
Steel sheet
Radioactive source

15. Detecting underground
leakage
Ratemeter record a high reading
above the leakage pipeGM-tube
Water added with radioactive sodium-24

16. Measuring the Wearing
Rate of Engine

17. Q & A
(Question and Answer)

18. 1) Which statement is true about the use of
radioactive substance?
A. To determine the sex of a foetus
B. To determine the contents in the
baggage of the air plane passengers
C. To detect leakage in underground
pipes
D. To identify counterfeit bank-notes
answer : C

19. 2) Which radioisotope can be used to
treat cancer ???
A. iodine-131
B. cobalt-60
C. carbon-14
D. uranium-238
answer : B

20. 3) Cobalt-60 destroys cancer cells
because it __________.
A has a long half-life
B has no side effect
C radiates gamma rays
D decays spontaneously
answer : C

21. 4) The radioactive radiation used in
radiotheraphy in the treatment for
cancer is ______??
A. Beta ray
B. Alpha ray
C. Gamma ray
D. X-ray
answer : C

22. 5) The radioisotopes which is used to
estimate the age of archeology
specimen is ________??
A. cobalt-60
B. carbon-14
C. iodine-131
D. sodium-24
answer : B

23. REFERENCE
O http://www.tutorvista.com/content/p
hysics/physics-ii/modern-
physics/radioisotopes.php
O http://spmphysics.onlinetuition.com.m
y/2013/08/uses-of-radioisotope-in-
industry.html
O http://www.youtube.com/
O Physics form 5 textbook

24. Special THANKS to all
physics teachers…
PHYSICS A +