21 radioactivity

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