The document provides an introduction to radioactivity, including the three main types of radioactive emissions (alpha, beta, gamma), their penetrating properties, safe handling of radioactive materials, and uses of radioisotopes. It defines key terms and includes sample test questions to assess understanding.

1. INTRODUCTION TO RADIOACTIVITY
Presenters: Damion Lawrence and MichaelWard

2. PREREQUISITE KNOWLEDGE
▪ For mastery of the content presented in this
presentation, students should have been taught:
– Atomic Structure
– The reason an atom is normally neutral and stable
– What is meant by the term Isotope

3. PRESENTATION OBJECTIVES
At the end of this presentation, students will:
i. be familiar with the phenomenon of radioactivity and the
safety measures when dealing with radioactive
substances.
ii. be able to state the nature of the three types of
radioactive emissions.
iii. be able to discuss the useful applications of
radioisotopes.

4. Radioactivity
(SECTION E: SPECIFIC OBJECTIVE 3.2 )
▪ Radioactivity, spontaneous disintegration of atomic
nuclei which accompanies the emission of
subatomic particles and electromagnetic energy
(i.e. alpha particle and beta particle, or of
electromagnetic and gamma rays).

5. TYPES OF NATURAL RADIOACTIVE EMISSIONS
(SECTION E: SPECIFIC OBJECTIVE 3.2 )
1. Alpha Radiation
(Alpha Particle)
2. Beta Radiation
(Beta Particle)
3. Gamma Radiation
(Gamma Ray)

6. ALPHA RADIATION
(SECTION E: SPECIFIC OBJECTIVE 3.2 )
▪ Alpha radiation
consists of alpha
particles. An alpha
particle is identical to
the nucleus of a helium
atom, which comprises
two protons and two
neutrons.

7. BETA RADIATION
(SECTION E: SPECIFIC OBJECTIVE 3.2 )
▪ Beta radiation consists of high
energy electrons emitted from
the nucleus.These electrons
have not come from the electron
shells or energy levels around
the nucleus. Instead, they form
when a neutron splits into a
proton and an electron.The
electron then shoots out of the
nucleus at high speed.

8. GAMMA RADIATION
(SECTION E: SPECIFIC OBJECTIVE 3.2 )
▪ Gamma radiation is very short
wavelength - high frequency -
electromagnetic radiation.This
is similar to other types of
electromagnetic radiation such as
visible light and X-rays, which can
travel long distances.

9. PENETRATING PROPERTIES OF RADIATION
(Section E )
▪ Radiation can be absorbed by substances in its path. For
example, alpha radiation travels only a few centimetres in
air, beta radiation travels tens of centimetres in air and
gamma radiation travels many metres. All types of
radiation become less intense the further the distance from
the radioactive material, as the particles or rays become
more spread out.

10. PENETRATING PROPERTIES OF RADIATION
▪ The thicker the substance, the more the radiation is
absorbed.The three types of radiation penetrate materials
in different ways.

11. PENETRATING PROPERTIES OF RADIATION (ALPHA RADIATION).
▪ Alpha radiation is the least penetrative. It can be stopped -
or absorbed - by just a sheet of paper.

12. PENETRATING PROPERTIES OF RADIATION (BETA RADIATION).
▪ Beta radiation can penetrate air and paper. It can be
stopped by a thin sheet of aluminum.

13. PENETRATING PROPERTIES OF RADIATION (GAMMA RADIATION).
▪ Gamma radiation is the most penetrative. Even small
levels can penetrate air, paper or thin metal. Higher levels
can only be stopped by many centimetres of lead or many
metres of concrete.

14. HANDLING RADIOACTIVE MATERIALS
(SECTION E: SPECIFIC OBJECTIVE 3.11 )
1. Radioactive materials
should be handled with
tools such as forceps-
never with the bare
hands
2. Sources should never be
pointed towards people
or other living organisms.
Sources should never be
brought near the eyes.

15. HANDLING RADIOACTIVE MATERIALS
(SECTION E: SPECIFIC OBJECTIVE 3.11 )
3. There must be no eating or
drinking where radioactive
materials are being used.
4. After use, radioactive
materials should be stored in
lead containers and placed in
a locked , isolated metal
cupboard.

16. HANDLING RADIOACTIVE MATERIALS
(SECTION E: SPECIFIC OBJECTIVE 3.11 )
5. After using radioactive
materials , the user must
wash his/her hands
thoroughly before eating.
6. Equipment capable of
detecting radioactivity must
be present to check for
radioactive emissions.

17. USES OF RADIOACTIVE ISOTOPES
(SECTION E: SPECIFIC OBJECTIVE 3.11 )
Radioactive isotopes have a variety of
applications.They are useful because we
can detect their radioactivity and we can
use the energy they release
 Radiometric dating:
radioactive isotopes are useful for
stablishing the ages of various objects.
The half-life of radioactive isotopes is
unaffected by any environmental factors,
so the isotope acts like an internal clock.

18. USES OF RADIOACTIVE ISOTOPES
(SECTION E: SPECIFIC OBJECTIVE 3.11 )
▪ The most common Radiometric dating
is known as Carbon Dating. By using
the half life of carbon-14 we can
determine the age of various objects
that were once living, such as bones.

19. USES OF RADIOACTIVE ISOTOPES
(SECTION E: SPECIFIC OBJECTIVE 3.11 )
 Irradiation of Produce
The radiation emitted by some
radioactive substances can be used
to kill microorganisms on a variety
of foodstuffs, which extends the
shelf life of these products.This
exposure kills a lot of the bacteria
that cause spoilage, so the produce
stays fresh longer. Eggs and some
meat, such as beef, pork, and
poultry, can also be irradiated.

20. USES OF RADIOACTIVE ISOTOPES
(SECTION E: SPECIFIC OBJECTIVE 3.11 )
 MEDICAL IMAGING
In nuclear medicine, tiny amounts
of a radioactive form of these
elements are introduced into a
patient’s body.The
“radioisotopes” are picked up by
specific organs, enabling a special
camera to take a picture of how
that organ is functioning in
striking detail

21. USES OF RADIOACTIVE ISOTOPES
▪ TRACERS
Radioactive isotopes are effective tracers
because their radioactivity is easy to detect.
A tracer is a substance that can be used to
follow the pathway of that substance
through some structure. For instance, leaks
in underground water pipes can be
discovered by running some tritium-
containing water through the pipes and then
using a Geiger counter to locate any
radioactive tritium subsequently present in
the ground around the pipes.

22. USES OF RADIOACTIVE ISOTOPES
(SECTION E: SPECIFIC OBJECTIVE 3.11 )
▪ CHEMOTHERAPY
Radiation damages the DNA of the
cancer cells, causing them to die.
Radiation therapy uses high-energy
radiation to shrink tumors and kill
cancer cells . X-rays, gamma rays, and
charged particles are types of
radiation used for cancer treatment.

23. SYMPTOMS OF RADIOACTIVE SICKNESS
(SECTION E: SPECIFIC OBJECTIVE 3.13 )
1. Loss of body hair
2. Nausea
3. Fatigue
4. Drop in white blood
cell count
5. Sterility after over-
exposure

24. QUESTION 1
Radioactivity is the:
a. Spontaneous disintegration of atomic nuclei which
accompanies the emission of subatomic particles and
electromagnetic energy.
b. nuclear energy required to achieve stability in the
nucleus of an atom.
c. nuclear energy required to split the nuclear of an atom
d. nuclear energy required to convert an element into a
different element

25. QUESTION 2
All are radioactive emissions EXCEPT:
a. Alpha Particle
b. Beta Particle
c. Gamma ray
d. Nuclear Fission

26. QUESTION 3
The most penetrative emission is:
a. Alpha Emission
b. Neutron
c. Beta Emission
d. Gamma Emission

27. QUESTION 4
All of the following are safety precautions when handling
radioactive materials EXCEPT:
a. Radioactive materials should be handled with tools such as
forceps-never with the bare hands.
b. Sources should never be pointed towards people or other
living organisms. Sources should never be brought near the
eyes.
c. There must be no eating or drinking where radioactive
materials are being used.
d. Radioactive materials should be placed in a plastic container
immediately after use.

28. QUESTION 5
Which emission has the furthest range:
a. Alpha Emission
b. Neutron
c. Beta Emission
d. Gamma Emission

29. QUESTION 6
All of the following are uses of Radioactivity EXCEPT:
a. Chemotherapy
b. Irradiation of Produce
c. Carbon Dating
d. Barcode reading

30. GLOSSARY OF TERMS
▪ Emission: the act of sending
out gas, heat, light, etc
▪ Fatigue: Fatigue is a term used to
describe the general overall
feeling of tiredness and/or a lack
of energy.

31. GLOSSARY OF TERMS
▪ Isotope : Any atom having
the same atomic number
but different mass number.
In other words, they have
the same number of
protons and electrons but
different number of
neutrons.

32. GLOSSARY OF TERMS
▪ Nuclei : plural of nucleus
( i.e. the central part of an
atom that comprises nearly
all of the atomic mass and
that consists of protons and
neutrons)

33. GLOSSARY OF TERMS
▪ Nausea: feeling an urge to
vomit.
▪ Spontaneous: unplanned or
occurring unexpectedly .

34. GLOSSARY OF TERMS
▪ Sterility: Not producing or
incapable of producing offspring
▪ Subatomic Particles: Particles that are
smaller than the atom are called
subatomic particles. The three main
subatomic particles that form an atom are
protons, neutrons, and electrons.