Class notes Assignment 1 - Pass level Task 1 (P2, P1)
Atomic structure
Types of nuclear radiation
Some atoms are .......................... and so they ............. nuclear radiation. There are
.............. types:
Merit Level (M1)
Web Quest. Use the links to answer the questions. Print off the completed research to help
you with the merit level of Assignment 3.1
http://www.darvill.clara.net/nucrad/types.htm
1. What are the three particles that make up an atom?
2. Radioactive decay is spontaneous. Highlight the statement that explains what spontaneous
means.
A. Strong magnetic fields can speed up radioactive decay.
B. Heating up a chemical makes decay slower.
C. Nothing you can do to the chemical affects when decay takes place.
3. What are the three types of radiation that can be emitted from a radioactive chemical?
4. “Because they have a large charge, alpha particles ionise other atoms strongly”. Use the
link to find out what ionise means; then return to the original page.
5. How ionizing are beta and gamma compared with alpha?
http://www.darvill.clara.net/nucrad/hlife.htm
1. What does the term half life mean?
2. Draw a graph of count rate against time for radioactive decay.
Use the interactive graph on the web site to find out
how to work out the half life of a radioactive material
from a graph.
3. Add some lines to your own sketch - like the red ones
on the screen - to show how to find half life.
http://www.glencoe.com/sites/common_assets/science/virtual_labs/E18/E18.html Scroll
down the side panel to reach the “Procedure” section. Watch the video if you like then follow
the instruction for gathering data and filling in the table. We will use the information next
lesson to draw some decay graphs and complete the merit section of the assignment.
Class notes Assignment 1 - Pass level Task 2 (P3)
Sign in to Doddle go to Resources tab at top of page – AQA IGCSE Physics-nuclear physicsatoms and radiation-dangers of ionization interactive.
http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/radiation/radioactiverev
6.shtml
1. In your own words describe the effect of radiation on living cells.
2. Use the information on the web page and your previous research to fill in the table below.
Radiation type
Ionizing power
alpha
Strongly ionizing
Effect when inside body.
beta
gamma
Least dangerous, most likely
to just pass through cells
Effect when outside
body
Merit level Task 2 (M2)
Sign in to Doddle go to Resources tab – AQA IGCSE Physics-nuclear physics-atoms and
radiation- Ionizing radiation Part 2 Using....
http://www.darvill.clara.net/nucrad/uses.htm
http://www.docbrown.info/page03/3_54radio05.htm
http://www.epa.gov/radiation/source-reduction-management/radionuclides.html
Copy the table below and use the information on these sites and any other source you need
(don’t forget to use books too!) to fill it in.
Used in:
Isotope and/or
type of radiation
used
How it works.
Smoke alarms
Alpha source
Normally inside the smoke detector alpha
particles ionize air so a current is produced.
Smoke gets in the way and stops this which
makes the alarm sound.
Am - 241
Thickness control
Sterilizing (food
and medical
instruments)
Radioactive
tracers
Checking welds
Cancer treatment
2. For each of the following describe the advantages and disadvantages of using that
radioactive isotope.
Americium 241 in smoke alarms
Technicium 99m in medical tracers
Cobalt 60 used in cancer treatment.
Distinction Level task 2 (D2)
Describe in more detail how and why isotope is used. You will need to include ideas about the
structure of the atom the type of radiation it emits and its half life.
Class notes Assignment 1 Pass level Task 3 (P4)
Nuclear Fission
1. Put the following statements in the correct order to describe a nuclear fission chain
reaction.
A slow-moving neutron is absorbed by an atom of
uranium-235.
Each of the three neutrons can be absorbed by
another atom of uranium-235.
This is known as a chain reaction.
This is known as nuclear fission.
Each of these uranium atoms undergoes fission,
releasing even more neutrons.
The uranium-235 becomes uranium-236, an unstable
isotope.
The uranium splits into two daughter nuclei and
three neutrons.
2. Use the following pictures to create a diagram of nuclear fission.
3. Construct an equation for nuclear fission.
235
92
U
236
92
U
141
56
B
a
+ + +
92
36
1
0
K 3
n
r
 
1
0
n
Extension:
4. Give two more examples of possible pairs of daughter nuclei.
5. What effect on the rate of reactions would there be if there were 5
neutrons emitted during each fission of uranium?
Nuclear reactors
Nuclear reactors use nuclear ......................... to
make heat. The heat is used to make ....................
and generate ....................................
..........................rods are used to change the speed
of the fission reaction. They are made of
........................... a chemical that soaks up (absorbs)
neutrons.
The fuel rods are surrounded by a ............................
The moderator is often made of ..............................
It slows the ............................... down so that fission
can happen more often.
Nuclear Fusion
Almost all the energy available on Earth came originally from the ................ The Sun and all
other stars use nuclear ............................ to make light and heat. Fusion is the joining of
.......................... nuclei like deuterium (an isotope of hydrogen) into heavier nuclei like helium.
This fusion produced lots of ............................. In the future we hope to be able to use nuclear
fusion to generate ......................................
Class notes Assignment 1 Pass level Task 3 (M3)