RADIOACTIVITYCombined Science 5129
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
1
Radiation
Nuclear Bombs!!!
DANGER
$%*!!
What Comes To Mind ...
... with the word ‘Radioactivity’
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
2
BOMBING OF JAPAN
WORLD WAR II, 1945
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
3
NUCLEAR ACCIDENT
THREE MILE ISLAND, NEW YORK, 1979
Radioactive materials were released to the environment due to
technical malfunction and human error from Nuclear Power Plant.
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
4
Explosion & fire at the nuclear power plant released radioactive particles to the
environment and spread throughout Europe.
NUCLEAR ACCIDENT
CHERNOBYL, 1986
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
5
SCENES FROM CHERNOBLY
THE AREA IS STILL HIGHLY RADIOACTIVE AFTER 27 YEARS!
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
6
NUCLEAR DISASTER
FUKUSHIMA, JAPAN, 2011
A series of equipment failures, nuclear
meltdown and release of radioactive materials
following the Tohoku earthquake and tsunami.
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
7
SOURCES OF NUCLEAR RADIATION
Cosmic Rays
Granite
Radon GasPotassium-40
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
8
Radioisotopes in medical procedures
Nuclear Power Stations
Fall-out from Nuclear Bombs
SOURCES OF NUCLEAR RADIATION
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
9
SOURCES OF NUCLEAR RADIATION
YOU
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
10
DISCOVERY OF NUCLEAR RADIATION
Henri Becquerel
Discover spontaneous radioactivity while
working with uranium salts in 1896.
The unit of radioactivity is the becquerel (Bq)
( 1852 - 1908 )
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
11
DISCOVERY OF NUCLEAR RADIATION
Becquerel crater on the Moon
Becquerel crater on Mars
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
12
DISCOVERY OF NUCLEAR RADIATION
Marie Curie
Formulated a theory of radioactivity, pioneered techniques for isolating radioactive isotopes, and
discovered two new elements, polonium and radium.
Introduced the term ‘Radioactivity’
( 1867 - 1934 )
The international standard for radioactive emission - the curie (Ci)
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
13
Discovered the radioactive elements Radium and Polonium
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
14
DISCOVERY OF NUCLEAR RADIATION
Radioactive elements in the Periodic Table
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
15
DETECTORS OF NUCLEAR RADIATION
Geiger-MullerTube Charged
Electroscope
Cloud Chamber
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
16
Photographic Films
DETECTORS OF NUCLEAR RADIATION
Radiation Badges P
repa
red
by
Cg
Ed
na
Mar
ia H
j Osm
an. E
-mai
l: e
dn
a.m
aria
.osm
an@
gm
ail.
com
17
ORIGINS OF NUCLEAR RADIATION
Unstable nucleus breaks up, releases tiny particles and waves of
energy
Nuclear radiation comes from the centre of unstable atoms.
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
18
Alpha Radiation
TYPES OF NUCLEAR RADIATION
Beta Radiation
Gamma Radiation
ThreeTypes of Nuclear
Radiation
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
19
USING CLOUD CHAMBER TRACKS
Straight, thick tracks
IDENTIFICATION OF NUCLEAR RADIATION
Thinner, wavy tracks
Short, irregular, thin tracks
Alpha Radiation
Beta Radiation
Gamma Radiation
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
20
NATURE OF NUCLEAR RADIATION2 protons and 2 neutrons
UnstableNucleus
Alpha Particle
Beta Particle
Gamma Rays
Same structure as Helium nucleus
High energy, fast-moving
electron
High energy, short
wavelength, electromagnetic
radiation
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
21
IONISING STRENGTH OF NUCLEAR RADIATION
+2 charge
UnstableNucleus
Alpha Particle
Beta Particle
Gamma Rays
Very strongly ionising
Less ionising than alpha particle,
more ionising than gamma rays
Least ionising
-1 charge
0 charge
Ionising strength tell us whether a particle has the ability to change other substances into ions.
Higher charge, Strongly Ionising
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
22
PENETRATING POWER OF NUCLEAR RADIATION
UnstableNucleus
Alpha Particle
Beta Particle
Gamma Rays
Very Weak,Least penetrating
radiation
More penetrating than alpha, less penetrating than
gamma
Strong,Most penetrating
radiation
Penetrating power tell us whether a particle has the ability to go through other substances
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
23
STOPPING NUCLEAR RADIATION
Few cm of airThin paperHuman skin
5 mm Aluminium Thick lead and few metres of concrete
Alpha RadiationBeta Radiation Gamma Radiation
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
24
UnstableNucleus
Alpha Particle
Beta Particle
Gamma Rays
Very hazardous if taken orally /
injected into the body
Most dangerous,Can penetrate
through deep body tissues
NUCLEAR RADIATION HAZARDS
Dangerous,Can penetrate
through human skin
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
25
NUCLEAR RADIATION HAZARDSLOW LEVEL EXPOSURE
Immediate Effects
Radiation Burns
Delayed Effects
Leukemia, Cancer, Cell Mutation
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
26
Immediate Death
NUCLEAR RADIATION HAZARDSHIGH LEVEL EXPOSURE
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
27
USES OF RADIOACTIVE ISOTOPES
Tracer
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
28
USES OF RADIOACTIVE ISOTOPES
RadiotherapyArchaeology
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
29
Thickness Gauge
USES OF RADIOACTIVE ISOTOPES
Sterilization
Surgical Tools
Food
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
30
SAFETY PRECAUTIONS
Using Radioactive MaterialsHANDLING RADIOACTIVE MATERIALS
Use tweezers for weak radioactive sources
Use remote control equipment for strong & dangerous radioactive
sources Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
31
Wear special protective clothing & film badges
SAFETY PRECAUTIONSHANDLING RADIOACTIVE MATERIALS
Using Radioactive Materials
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
32
Keep in lead containers with walls few cm
thick.
SAFETY PRECAUTIONSHANDLING RADIOACTIVE MATERIALS
Storing Radioactive Materials
Radiation Symbol Displayed &
containers labelled ‘Radioactive
Source’
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
33
SAFETY PRECAUTIONSHANDLING RADIOACTIVE MATERIALS
Disposal of Radioactive Materials
Deep in underground/underwater vaults lined with thick lead-cement
walls
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
34
NUCLEAR REACTIONS
Decay
Fission
Fusion
ThreeTypes of Nuclear
Reactions
Alpha Decay
Beta Decay
Gamma Decay
Nuclear Power Plants
Formation of Stars & Galaxy
Nuclear Bombs
Formation of ElementsFuture Nuclear Power Plants
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
35
NUCLEAR DECAYRADIOACTIVE DECAY
The breakdown of radioactive unstable nuclei to form stable nuclei of other elements by emitting alpha particles or beta particles.
It is a random process, spontaneous and cannot be controlled.
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
36
NUCLEAR DECAYHALF-LIFE
The average time taken for half the number of atoms in any given sample of a radioactive element to decay.
The half-life of a sample radioactive isotope can be determined from its decay curve.
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
37
NUCLEAR DECAY
Average number of decay
per second
HALF-LIFE & DECAY CURVE
First, find the original value for the activity
Becquerel (Bq)
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
38
NUCLEAR DECAYHALF-LIFE & DECAY CURVE
Second, find half of the original value for the activity
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
39
NUCLEAR DECAYHALF-LIFE & DECAY CURVE
Thirdly, find the time taken for half of the original value for the activity to happen.
This value is the half life of the radioactive sample.
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
40
NUCLEAR DECAYHALF-LIFE & DECAY CURVE
The half life of a radioactive sample is the same throughout its decay process.
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
41
Alpha Decay
Beta Decay
Gamma Emission
ThreeTypes of Nuclear
Decay
NUCLEAR DECAYRADIOACTIVE DECAY EQUATION
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
42
Alpha Decay
NUCLEAR DECAYRADIOACTIVE DECAY EQUATION
When an atom decays by alpha emission, its nucleon number A decreases by 4 and its proton number Z decreases by 2
XA
ZY
A - 4
Z - 2 He4
2+
Parent nucleus
Daughter nucleus
Alpha particle
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
43
NUCLEAR DECAYRADIOACTIVE DECAY EQUATION
Beta Decay
XA
ZY
A
Z + 1 e0
-1+
Parent nucleus
Daughter nucleus
Beta particle
When an atom decays by beta emission, its nucleon number A remains the same but its proton number Z increases by 1
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
44
NUCLEAR DECAYRADIOACTIVE DECAY EQUATION
Gamma EmissionWhen an atom decays by gamma emission, it has no effect on both its
nucleon number A and its proton number Z.
XA
ZX
A
ZƔ+
Parent nucleus
Daughter nucleus
Gamma rays
Pre
pare
d b
y C
g E
dn
a M
aria
Hj O
sman
. E-m
ail:
ed
na.
mar
ia.o
sman
@g
mai
l.co
m
45
Top Related