Download Nuclear - Calderglen High School

Nuclear
Nat 5
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Why is radiation emitted
from atoms?
Because there nucleus
is unstable. Due to the
proton to neutron ratio.
A alpha particle consists
of…
2 protons and 2 neutrons:
it is a a helium atom.
Beta radiation is
described as …
A high speed electron
Gamma radiation is
described as …
A wave
Alpha is stopped by…
Thin paper and a few cm
of air.
Beta is stopped by…
Thick lead, concrete and
Aluminium.
Gamma is stopped by…
Concrete or lead.
6g of a radioactive isotope of
60Co has a half-life of 5 yrs. how
much of this isotope would be
left after 20 yrs?
The half life of a radio active isotope is a measure of the
time is takes for activity to be reduced by half. Over a
period of 20 years, 4 half-lives would be needed .
60Co
6g
60Co
3g
60Co
1.5g
60Co
0.75g
60Co
0.375g
What is the result of an
atom losing an alpha 
particle?
An alpha particle is a helium nucleus. So is
made up from 2 protons and 2 neutrons.
It has a atomic number of 2 and a mass
number of 4.
So the atomic number decreases by 2
and the mass number decreases by 4.
What type of reaction is
occurring in the process below?
236
92
U
142
56
Ba
+
91
36
Kr
+
3
1
0
Nuclear fission this involves the splitting
of a nucleus into two nucleui.
What is produced (X) when 238U
is combined with a neutron.
1
n
0
X=
239
93
Pu
+
238
U
X
+
0
-1 e
Adding a neutron means the
mass number will
increase by 1, but the atomic
number will not change.
131I
can be used to study diseased thyroid
glands. Its half-life is 8 days. A patient
was given 0.0053 mol of this isotope. How
many grams would be left after 16 days?
The mass of 131I in 0.0053g = n (number moles) =
mass/gfm
So mass = n x gfm
=
0.0053x131
=
0.694g
131I
0.694g
8
131I
0.347g
16
131I
0.174g