i.
ii.
iii.
Forbidden
energy
gap
at
300
K
Electron
mobility
at
300
K
Fano
factor
Si
1.115
eV
1350
cm
2
V
1
s
1
.·
0.08

0.14
Ge
0.665
eV
3900
cm
2
V
1
s
1
0.05

0.12
(60
marks)
RADIOISOTOPE
UNIT:
Sc87102
p.
9
3.
(A)
Discuss
the
concepts
of
specific
ionisation
and
range
in
relation
to
ionising
radiation.
Use
these
concepts
to
explain
the
seemingly
paradoxical
situation
in
which
alpha
particles
are
less
harmful
than
gamma
rays
for
external
hazard,
but
for
internal
hazard
the
opposite
is
the
case.
(30
marks)
(B)
The
instantaneous
dose
rate,
R
13
in
_Gy
s
1
to
tissue
containing
C,
MBq_
kg
1
of
a
betaemitter
of
average
energy
E
13
in
joule
is
given
by
R
13

10
6
CE
13
•
The
internal
beta
dose
accumulated
in
a
given
time
can
be
calculated
from
D
where
D
absorbed
dose
in
Gy
~

effective
halflife
in
days
f

fraction
remaining
at
end
of
time
period
Use
this
information
and
graph
paper
to
calculate
i.
the
instantaneous
dose
rate
ii.
the
dose
delivered
over
the
first
10
days
when
37
MBq
of
C14
labelled
drug
is
injected
intravenously
into
an
animal
containing
540 g
of
blood.
(Assume
the
biological
halflife
for
the
drug
is
lOO
days
and
the
average
energy
for
C14
is
8 x
10
15
joule)
(30
marks)
4.
(A)
In
a
radioactive
series
A~
B
~
C,
prove
that
the
disintegration
rate
of
the
parent
nuclide
A
will
equal
the
disintegration
rate
of
the
daughter
nuclide
B when
secular
equilibrium
has
become
established.
(30
marks)
(B)
i.
Describe
with
examples
the
system
of
nomenclature
for
labelled
compounds.
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 Fall '17
 R
 Ionizing radiation