- PHYSICS
TOMIC
RADIOACTNVITY
Thomson model Rutherford
:
:
's
( Blum pudding theory atoms were not stable 4 emitted radiation
)
5
atoms had a nucleus
+ -
t
uniformly density
+
not distributed or
charge
.
t t
-
+ +
.3 types of radiation alpha bera gamma
:
.
,
,
Goldarom
meaning of the diagram L
o
:
@
o
most X particles foil
went
straight through
o
latom as
mostly space o
}
Goldnusiews
o
SUME were deflected langle qo o
900)
@
oFEW swere deflected langle L
o
oruclei most mass dense tre
very charge
s
Qo
,
,
-1
O
oalpna fast posilevely charged particles
:
@
-moving
ss
Alphadeflecred
o
L
AlBha bouncing back
Radiation emission of energy in the form oF EM waves Or particles
.
o
Nuclear radiation radiation emmiled when nucleus decays
:
o
lonising radiation any radiation wl enough energy to ionise atoms
:
Rutherford
..
conclusion
:
's
radiation
3 ty Bes of nuclear
tonisation
:
o 1 positive
7 neutral
7 negarive oiunisation chamber
o
positive is more massive than
negative
o
picoammeler
o
negative s relative
charge of -1 RESULTS
:
opositive t - ionisation
relative
charge of
strong
s
Aradiation:
2
lionisation ceases beyond a certain distance
few
fradiation
range air cm
in
:
.
in air varies wß to metre
- a or more
range
s
fewer ions per mmn than a
-partices
f ionising
than a and
B
we a k r
-radiation:
, NUCLEAR RADIUS AND DENSITY
:
Electron
r a can be
diffractiond uus
used to estimate nuclear
EN WHy only protonst neutrous interact wy strong nuclear force
?
intensity variesw diffraction
angle
relative nuclear radius is Tiny compared to the
^ intensity
of electrons
Alomic raaius
ü
TiB Imsersity rever
.
?:
~
Hits zero just gess v close
.
intersityw angle of diffraction radius of atom :005 (5
,
,
as
mm
x10"m)
L 7
angle of diffraction O
nucleus is made up of Nucleons
:
.
nuclear radius
more nucleons
bigger is proportional to CUBE root of number
-
nucleon
.
Y
po
linear relationship between R and -
3
s RaA
'
R RoA
T
?
L Ro ^
"
=
=1.4fm)
.
nusleon namber (
AS
s
B
Wuclean Number {
A)
density of nuclear matter ENORMOUS
:
and similar
protons neutrons
nearly same mass
density
s :
nuclear 1.45 101 kgm
density -
-3
x
atoms contain lots of empty space most of the mass is in the smale nucleus
.
,
RADIOACTIVE EMISSIONS
.
if nucleus is unstable :
break down to become more stable nucleus decays by releasing energy
:
instability due to too
many
or not
enough neutrons and or particles astable form
:
Or too much radioactive decay
energy
s
.
.
lone single decay is RANDOR
)
radio active emissions ionising radiation C knocked off electrons
sion
:
)
TOMIC
RADIOACTNVITY
Thomson model Rutherford
:
:
's
( Blum pudding theory atoms were not stable 4 emitted radiation
)
5
atoms had a nucleus
+ -
t
uniformly density
+
not distributed or
charge
.
t t
-
+ +
.3 types of radiation alpha bera gamma
:
.
,
,
Goldarom
meaning of the diagram L
o
:
@
o
most X particles foil
went
straight through
o
latom as
mostly space o
}
Goldnusiews
o
SUME were deflected langle qo o
900)
@
oFEW swere deflected langle L
o
oruclei most mass dense tre
very charge
s
Qo
,
,
-1
O
oalpna fast posilevely charged particles
:
@
-moving
ss
Alphadeflecred
o
L
AlBha bouncing back
Radiation emission of energy in the form oF EM waves Or particles
.
o
Nuclear radiation radiation emmiled when nucleus decays
:
o
lonising radiation any radiation wl enough energy to ionise atoms
:
Rutherford
..
conclusion
:
's
radiation
3 ty Bes of nuclear
tonisation
:
o 1 positive
7 neutral
7 negarive oiunisation chamber
o
positive is more massive than
negative
o
picoammeler
o
negative s relative
charge of -1 RESULTS
:
opositive t - ionisation
relative
charge of
strong
s
Aradiation:
2
lionisation ceases beyond a certain distance
few
fradiation
range air cm
in
:
.
in air varies wß to metre
- a or more
range
s
fewer ions per mmn than a
-partices
f ionising
than a and
B
we a k r
-radiation:
, NUCLEAR RADIUS AND DENSITY
:
Electron
r a can be
diffractiond uus
used to estimate nuclear
EN WHy only protonst neutrous interact wy strong nuclear force
?
intensity variesw diffraction
angle
relative nuclear radius is Tiny compared to the
^ intensity
of electrons
Alomic raaius
ü
TiB Imsersity rever
.
?:
~
Hits zero just gess v close
.
intersityw angle of diffraction radius of atom :005 (5
,
,
as
mm
x10"m)
L 7
angle of diffraction O
nucleus is made up of Nucleons
:
.
nuclear radius
more nucleons
bigger is proportional to CUBE root of number
-
nucleon
.
Y
po
linear relationship between R and -
3
s RaA
'
R RoA
T
?
L Ro ^
"
=
=1.4fm)
.
nusleon namber (
AS
s
B
Wuclean Number {
A)
density of nuclear matter ENORMOUS
:
and similar
protons neutrons
nearly same mass
density
s :
nuclear 1.45 101 kgm
density -
-3
x
atoms contain lots of empty space most of the mass is in the smale nucleus
.
,
RADIOACTIVE EMISSIONS
.
if nucleus is unstable :
break down to become more stable nucleus decays by releasing energy
:
instability due to too
many
or not
enough neutrons and or particles astable form
:
Or too much radioactive decay
energy
s
.
.
lone single decay is RANDOR
)
radio active emissions ionising radiation C knocked off electrons
sion
:
)
