OCR GCSE
Additional Science
Homework P4a Foundation
Sparks
1
There are two sorts of electronic charge. What are they called?
2
Rachel combs her hair. She puts her comb near to some small pieces of paper. What
will happen to the paper?
3
Some materials can be charged by rubbing them with a cotton duster.
Choose from the list the materials that will become charged if rubbed with a cotton
duster.
copper
4
polythene
nylon
silver
steel
Franco plays football on a synthetic pitch. He gets an electrostatic shock when he
touches a goal post. Explain why.
5
Static electricity can sometimes be a nuisance and sometimes be dangerous.
(a) Write down two examples where static electricity is a nuisance.
(b) Write down two examples where static electricity is dangerous.
6
Ben charges two identical balloons by rubbing them on his sleeve.
He puts the two balloons together. What will happen to the balloons? Explain your
answer.
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OCR GCSE
Additional Science
Homework P4a Higher
Sparks
1
Andy rubs a plastic rod on a cloth. It gets a positive charge.
(a) What charge does the cloth get?
(b) It becomes charged because charged particles move from one object to another.
(i) What is the name of these charged particles?
(ii) What charge do these particles have?
(iii) How does the plastic get a positive charge?
2
It is easy to get an electric shock – you sometimes get one just getting out of a car.
(a) Why do you sometimes get an electric shock getting out of a car?
(b) What can you do to avoid getting this shock?
3
Lorries carrying cylinders of hydrogen (a very flammable gas) have a notice on the
back stating “This lorry must be earthed before loading or unloading.” Explain why.
4
Apart from earthing, suggest two other ways of reducing the chance of a shock and
explain how they work.
5
Many fabric conditioners have anti-static properties to stop clothes from clinging.
Use websites/library/manufacturers’ information, etc., to find out how anti-static
liquids work.
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OCR GCSE
Additional Science
Homework P4b Foundation
Uses of electrostatics
1
Ian is a doctor and uses a defibrillator to restart a patient’s heart when it has stopped.
(a) Describe how this is done.
(b) What safety precautions need to be taken when using a defibrillator?
2
Large car companies use electrostatics to paint cars. They charge the spray gun and the
car body.
(a) Why do they charge the spray gun?
(b) Why do they charge the car?
(c) What is the advantage of using this method of painting?
3
Electrostatics has many uses. Write down two.
4
Use websites/library to investigate how coal-fired power stations use electrostatics to
remove dirt and smoke from their chimneys.
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OCR GCSE
Additional Science
Homework P4b Higher
Uses of electrostatics
1
Static electricity is used to restart a patient’s heart using a defibrillator.
(a) Gel is sometimes put onto the patient’s chest before the paddles are applied.
Suggest a reason why.
(b) The operator gives the instruction ‘stand clear’ before using the defibrillator.
Explain why.
(c) What effect does the passing of a large current through the heart have?
2
Draw a diagram and use it to explain how electrostatic dust precipitators remove smoke
particles from chimneys.
3
Electrostatics is useful in paint spraying. The spray nozzle is at a high potential and
gives the paint a charge.
(a) What effect does this have on the droplets of paint?
(b) What would happen if the paint was not charged?
(c) What charge is put onto the car?
(d) What effect does this have on the paint?
(e) What are the advantages of using this method of spraying cars?
4
Farmers use a similar method to spraying cars when they put chemicals on crops. This
costs more than normal methods and it is not possible to connect plants to a high
potential. Try to find out why this method is used and how it works.
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OCR GCSE
Additional Science
Homework P4c Foundation
Safe electricals
1
Look at the diagram of a plug. There are three wires
A
attached to the plug: live neutral and earth.
Terminal
Name of wire
Colour of wire
C
B
(a) Redraw the table and complete.
(b) What is the job of (i) the live wire
2
(ii) the neutral wire
(iii) the earth wire?
Gabby builds the following circuit.
X
She has three resistors, 8 ohms, 6 ohms and 4 ohms.
(a) Which resistor should she use if she wants the lamp to be as bright as possible?
(b) (i) There is a fuse in the circuit. Why is a fuse put into an electrical circuit?
(ii) How does a wire fuse work?
3
In the circuit shown, the reading on the ammeter is 3 amps the reading on the voltmeter is 15
volts. Calculate the resistance.
A
V
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OCR GCSE
Additional Science
Homework P4c Higher
Safe electricals
1
Three wires can be connected inside a normal plug.
(a) What is the job of:
(i) the live wire?
(ii) the neutral wire?
(iii) the earth wire?
(b) Double insulated appliances do not have an earth wire. Explain why.
2
Electrical appliances usually have a fuse.
(a) Which wire is the fuse connected to?
(b) How does a wire fuse work?
(c) Explain how this protects the appliance if it develops a fault.
3
To protect people, an earth connection and a fuse can be used together. How does this
combination protect people?
4
Des uses the following circuit to find the resistance of a lamp:
power
supply
A
V
Brightness of bulb
Current
Voltage
bright
3A
12V
dim
2A
6V
Resistance
(a) Complete the table of results to find the two missing resistances.
(b) How does the resistance change with the brightness of the lamp?
(c) Suggest a reason for this change.
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OCR GCSE
Additional Science
Homework P4d Foundation
Ultrasound
1
(a) What is meant by ultrasound?
(b) What sort of wave is an ultrasound wave?
2
All waves have the same features. What is meant by:
(a) amplitude?
(b) wavelength?
(c) frequency?
3
What is the approximate frequency of an ultrasound wave?
4
Ultrasound can be used to measure the speed of blood flow in the body. Use websites/
library/textbooks to find out how ultrasound measures the speed of blood in the body.
5
Ultrasound waves have compressions and rarefactions.
(a) Draw a diagram of an ultrasound wave to show:
(i) a compression.
(ii) a rarefaction.
(b) mark one wavelength on your diagram.
(c) find out if ultrasound can be used in space.
(d) write down two uses of ultrasound.
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OCR GCSE
Additional Science
Homework P4d Higher
Ultrasound
1
Ultrasound is a longitudinal wave with a frequency greater than 20,000 Hz.
(a) What is a longitudinal wave?
(b) Describe the motion of the particles in both a longitudinal wave and a transverse
wave.
(c) What is meant by frequency?
2
(a) Apart from body scans, write down one other medical use of ultrasound.
(b) Explain how ultrasound is used for body scans.
(c) Original ultrasound scans were done under water with the scanner in a plastic bag
to keep it dry. Today, a clear gel is used on the patient’s skin and the head. Try to
find out why this is necessary.
3
In many cases ultrasound is used for scans instead of X-rays. Explain the advantages of
using ultrasound.
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OCR GCSE
Additional Science
Homework P4e Foundation
Treatment
1
(a) Copy and complete the following table, putting yes and no in the boxes.
Radiation
Electromagnetic
Used as a tracer
yes/no
yes/no
alpha
beta
gamma
X-rays
(b) X-rays and gamma rays are similar in some ways and different in other ways.
(i) Make a list of the ways in which X-rays and gamma rays are similar.
(ii) Make a list of the ways in which X-rays and gamma rays are different.
2
Alpha rays cannot be used a tracers. Suggest reasons why.
3
When radiation is used in medicine, the amount used is always as small as possible.
Explain why.
4
Doctors suspect that a patient has a blood clot in their leg. They decide to use a tracer to
find out.
(a) What is a tracer?
(b) What sort of material is used as a tracer?
(c) How does the tracer get into the bloodstream?
(d) What would they expect to find just before the blood clot?
(e) What would they expect to find just after the blood clot?
(f) What is the advantage of using a tracer?
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OCR GCSE
Additional Science
Homework P4e Higher
Treatment
1
Gamma rays and X-rays are produced in different ways.
(a) (i) How are gamma rays produced?
(ii) How are X-rays produced?
(b) Why do doctors prefer to use X-rays instead of gamma rays for treatment in
hospitals?
2
Doctors use gamma rays to treat cancer.
They rotate a gamma source around the patient.
Explain how the treatment works.
3
Doctors decide to use a tracer to look for a blockage in a blood vessel.
(a) What sort of material do they use as a tracer?
(b) How does it get into the patient?
(c) How would they know when they had found a blockage?
(d) What is the advantage of using tracers?
4
Engineers think that there is a leak in an oil pipeline. They put some radioactive
material into the pipe and follow the path of the pipe on the surface.
X
Y
Z
flow of oil along pipeline
(a) What sort of radiation would the radioactive material give out?
Explain your answer.
(b) What instrument is used to detect the radiation?
(c) How would you expect the readings to differ as they move along the pipe?
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OCR GCSE
Additional Science
Homework P4f Foundation
What is radioactivity?
1
What is radioactivity?
2
Copy and complete the sentence below:
The three types of nuclear radiation are _______, _______ and _______.
3
(a) Which part of the atom does nuclear radiation come from?
(b) The count rate for a nuclear source is 3500 counts per minute. What does this
mean?
(c) What happens to the count rate of a radioactive source as time goes on?
4
What are the differences between alpha, beta and gamma radiations? Research these
different radiations and try to discover:
(a) what they are made of.
(b) their mass.
(c) their charge.
(d) their penetrating power.
(e) their ionising power.
(f) their uses.
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OCR GCSE
Additional Science
Homework P4f Higher
What is radioactivity?
1
(a) What is meant by half-life?
(b) Mandy investigates the half-life of a radioactive material. The table shows her
results.
0
10
20
30
40
50
60
70
80
120
75
47
30
25
12
8
5
3
Time (s)
Count rate (cps)
(i) Plot a graph of these results on graph paper and use your graph to calculate the
half-life.
(ii) One result does not fit the graph. Which one?
(iii) Suggest a
reason why this point may not fit the graph.
2
Doctors need to give a patient a radioactive tracer. They have a choice of four tracers.
Information about the tracers is given in the table.
Tracer Half-life (hours)
Radiation emitted
1
0.25
alpha
2
1.00
beta
3
6.00
beta
4
100.00
gamma
Which is the most suitable tracer? Explain: (a) Why you chose your answer.
(b) Why you rejected the others.
3
Copy the table below and fill it in to show what happens to the nucleus when an alpha
particle is given off.
mass number
number of neutrons
number of protons
charge
4
(a) Plutonium 21884Po decays to give an alpha particle and a lead atom.
(i) What do the numbers 218 and 84 represent?
(ii)Write the decay equation for
the above process.
(b) Carbon dating involves the decay of the 146C isotope by beta decay. Complete the
decay equation for the above process.
14
6C
N +
o
_-1e
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OCR GCSE
Additional Science
Homework P4g Foundation
Uses of radioisotopes
1
There is radiation in the environment that is always present.
(a) What do we call this radiation?
(b) What causes this radiation?
(c) This radiation is much higher in some parts of the country than others. Use
websites/textbooks to find out where it is higher and why.
2
Apart from medical uses, suggest two other uses for radioactive tracers.
3
An alpha source is used in some smoke detectors. Explain how this type of smoke
detector works.
4
Radioactivity can be used to tell how old rocks are.
(a) Which element is used to give a date to old materials?
(b) A special isotope is used for this purpose. Use a dictionary to find the meaning of
isotope.
5
A paper mill uses a radioactive isotope to keep the thickness of the paper correct. The
detector measures the amount of radiation passing through the paper.
radioactive
source
paper
radioactive
detector
(a) What sort of source (alpha, beta or gamma) should be used? Explain your answer.
(b) What will happen to the count rate if the paper is too thin?
(c) A source with a long half-life is used. Suggest why.
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OCR GCSE
Additional Science
Homework P4g Higher
Uses of radioisotopes
1
Some background radiation comes from natural sources and some is man made. Write
down two man-made sources of background radiation.
2
Nick needs to find a blockage in his drain. He has some radioactive liquid and a
detector.
(a) Describe how he would use these to find the blockage, giving details of the type of
radiation, and the results he would expect from the meter.
(b) Radioactive isotopes can be used as thickness gauges. A paper mill uses a
radioactive isotope to keep the thickness of the paper correct. The detector
measures the amount of radiation passing through the paper.
radioactive
source
paper
radioactive
detector
(i) What sort of source (alpha, beta or gamma) should be used? Explain your
answer.
(ii) What will happen to the count rate if the paper is too thin?
(iii) A source with a long half-life is used. Suggest why.
3
Measurements of the amount of radioactive carbon can give an approximate age for
some materials. Explain how this is done.
4
An alpha source is used in some smoke detectors. Explain how this type of smoke
detector works.
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OCR GCSE
Additional Science
Homework P4h Foundation
Fission
1
Most power stations use coal, gas or oil as a fuel. What fuel does a nuclear power
station use?
2
Describe the main process stages in a nuclear power station. The first and last ones are
done for you.
Fuel taken into power station ______________________________________________
_______________________________________ electricity transmitted to national grid.
3
(a) What is meant by a chain reaction?
(b) What is the difference between a chain reaction in a power station and that in a
nuclear bomb?
(c) A lot of water from nuclear power stations is radioactive. How does this water
become radioactive?
4
When some nuclear fuel splits it gives out energy in a nuclear reactor. What name is
given to this process?
5
One advantage of using nuclear power is that it does not give out carbon dioxide.
(a) Find out about the other advantages and the disadvantages of using nuclear fuel to
produce electricity.
(b) Design a leaflet to either (i) say why we should have nuclear power OR (ii)
campaign against the building of nuclear power plants.
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OCR GCSE
Additional Science
Homework P4h Higher
Fission
1
In order to generate heat, an atom of uranium splits. This is called nuclear fission.
(a) Describe what happens to an atom of uranium causing the nucleus to split.
(b) How does this lead to a chain reaction?
2
Look at the diagram of a nuclear reactor and use it to help you answer the following
questions.
control and charge face
hot gas
thick
concrete
shield
steam to
turbine
generating
plant
boron
control
rods
boiler
graphite
core
steam
drum
uranium
rods
pressure
vessel
water
cool gas
(a) What happens to all the materials inside the reactor?
(b) Why is there a thick concrete shell around the reactor?
(c) How is heat energy removed from the reactor core?
(d) Why is the water/steam produced outside the reactor?
(e) What are control rods?
(f) How are they used?
(g) Why are they made of boron?
(h) Try to find out why the fuel (uranium) rods are surrounded by graphite.
3
Nuclear reactors produce radioactive waste.
(a) Why is it difficult to get rid of waste from power stations?
(b) A nuclear reactor produces 1000 kg of nuclear waste. The half-life is 5 years. How
long will it take to get down to about 1 kg of nuclear waste?
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OCR GCSE
Additional Science
Homework Mark Scheme
P4a &P4b Foundation & Higher
P4a Sparks
P4b Uses of electrostatics
Foundation
Foundation
1
2
1
3
4
5
6
Positive/negative
each [1]
Move/attracted
[1]
towards comb
[1]
Polythene and nylon
each [1]
Idea of friction/rubbing
[1]
between feet/trainers and pitch
[1]
Franco becomes charged
[1]
Goal post is a conductor
[1]
Charge flows from Franco to earth
[1]
Electrons flow
[1]
(a) clothing clings, records become dirty,
TV screens/monitors attract dirt, plastic
containers become dirty, shock when
getting out of car
each [1] max [2]
(b) lightning: refuelling cars/planes, etc; in
dusty atmospheres
e.g. flour mills
each [1] max [2]
The balloons will repel
[1]
Both have the same charge
[1]
Like charges repel
[1]
Higher
1
2
3
4
5
(a) Negative
(b) (i) Electrons
(ii) Negative
(iii) It loses electrons
(a) Friction
between your clothes
and the seat
causes charge to build up
This is earthed/flows to earth when you get
out
This movement of charge causes a shock
(b) Connect the car to earth with a
conducting strip
This removes the charge from the car
The gas rubs along the pipes
during loading or unloading
The pipe and gas are insulators
The charge can build up
If a spark occurs it can cause an explosion
Earthing prevents charge building up
so no chance of spark
Use of rubber mat
Rubber/plastic soled shoes
provide high resistance
to earth
so current cannot give shock
Ideas that: they prevent charge building up,
allow the charges to cancel out, some make
the clothing a partial conductor
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
2
3
4
Higher
1
2
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
(a) Paddles charged
[1]
good contact/conducting gel placed on
patient’s chest
[1]
charge passes through heart
[1]
causing it to contract
[1]
(b) Care not to shock doctor/other staff
[1]
(a) To put identical charge into the paint
[1]
Droplets become charged/repel
[1]
Keeps them as a fine mist/prevents
coalescing
[1]
(b) To attract the paint
[1]
(c) Provides an even coat
[1]
Less waste [1] shadow painted [1]
[2]
Better finish
[1]
Photocopiers/printers
each [1] max [2]
Ideas to include: charged metal plates in
chimney; dirt/ash attracted to plates falls
back down chimney when large enough
particles are formed.
[4]
3
(a) To give a good electrical contact/
reduce contact resistance
(b) So that only the patient gets an
electric shock
The energy is high enough to kill people
(c) Causes the muscles to contract
Diagram to show chimney
with grids of charges wires
alternating + and −
Particles become charged
Attracted to oppositely charged wires
Clump together
Fall down chimney
due to gravity
(a) Causes them to repel
and produce a fine mist
(b) Would go together in large drops
(c) The opposite to the paint
(d) Paint is attracted to the car
(e) Even coat/less waste/shadows painted
each
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[3]
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OCR GCSE
Additional Science
Homework Mark Scheme
P4c &P4d Foundation & Higher
P4c Safe electricals
P4d Ultrasound
Foundation
Foundation
1
2
3
(a) A earth [1] green/yellow [1]
B live (1) brown (1)
C neutral (1) blue (1)
(b) (i) Carries the high voltage
(ii) Second wire to complete the
circuit
(iii) A safety wire to stop the
appliance becoming live
(a) 4 ohms
(b) (i) Safety
(ii) If too large a current flows
wire melts/breaks/blows
R = V/I
= 15/3
= 5 ohms
[2]
[2]
[2]
[1]
1
2
[1]
3
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
4
5
Higher
1
2
3
4
(a) (i) Carries a high voltage
(ii) The second wire to complete the
circuit
(iii) Safety wire to stop the
appliance becoming live
(b) The case is a non-conductor/made of
plastic/insulator
The case cannot become live
(a) Live wire
(b) Too much current flowing in the
circuit
Wire melts/breaks/blows
(c) Fuse cuts off current
preventing further heating/damage
Earth wire is connected to case
If there is a fault making case live
current flows to earth
more easily through wire than person
This large current blows the fuse
(a) R = V/I
Bright: R = 12/3 = 4 ohms
Dim: R = 6/2 = 3 ohms
(b) Resistance increases with brightness
(c) The lamp gets hotter as it gets
brighter
[1]
[1]
[1]
Higher
1
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
(a) High-frequency sound waves [1] too
high to hear/ above 20,000 Hz [1]
[2]
(b) longitudinal
[1]
(a) Maximum displacement from mean
position
[1]
(b) Shortest distance between two identical
point on wave
[1]
(c) Number of vibrations each second
[2]
Any answer between 20,000 and 1,000,000
Hz
[1]
Ideas to include: aimed along blood vessel,
frequency of return wave measured,
frequency changes because of movement,
possible mention of Doppler effect, change
in frequency calculated, this change relates
directly to speed of blood flow.
(a) Correct drawing of longitudinal wave
showing (i) compression; (ii) rarefaction
[2]
(b) Wavelength between two compressions
or rarefactions
[1]
(c) Cannot be used in space
[1]
Medium needed for propagation
[1]
(d) Scanning/smashing kidney
stones/cleaning/sonar
any [2]
2
3
(a) A wave where the particles vibrate
along the direction of the wave
(b) Longitudinal particles vibrate parallel
to wave direction
[1]
[1]
wave direction
vibration
Transverse particles vibrate at right angles
to the wave direction
[1]
wave direction
vibration
(c) number of vibrations each second
(a) Breaking kidney stones
(b) Waves sent in pulses [1] into the body
[1]; waves reflected [1] from different
layers [1]; time to receive reflection
measured [1]; different times mean
different depths [1]; this is used to produce
an image [1]
(c) Ultrasound cannot pass through air [1];
it is totally reflected [1]; there must be no
air gap between patient and ultrasound
head [1] otherwise no image is formed [1]
It can produce images of soft tissue
It does not damage living cells
[1]
[2]
[1]
[7]
[4]
[1]
[1]
[1]
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OCR GCSE
Additional Science
Homework Mark Scheme
P4e & P4f Foundation & Higher
P4e Treatment
P4f What is radioactivity?
Foundation
Foundation
1
(a)
Radiation
1
Electromagnetic
Used as a
yes/no
tracer yes/no
alpha
No
No
beta
No
Yes
gamma
Yes
Yes
X-rays
Yes
No
2
3
4
[8]
2
3
4
(b) (i) same wavelength; same
frequency; same penetration; damage/kill
living cells; used to treat cancer
(ii) differences: gamma comes from the
nucleus of a radioactive atom; X-rays
made by electrons striking a target;
gamma can be used as tracer; X-rays
cannot be used as tracer; X-rays used to
take images of broken bones
Unable to be detected outside the body
Radiation can damage living cells
Using small doses limits this damage
(a) A substance that can be followed as it
goes round the body [1] by an outside
detector [1]
(b) radioactive
(c) injected
(d) high count rate
(e) low/no count rate
(f) reduces the need for surgery
[5]
[5]
[1]
[1]
[1]
[2]
[1]
[1]
[1]
[1]
[1]
Higher
1
2
(a) (i) Gamma rays are from the nucleus
of an atom
(ii) X-rays are produced when highspeed electrons [1] hit a metal target [1]
(b) They are easier to control
They can be switched on and off
Radiation penetrates the body
Focused on the tumour/cancer
Destroys/damages/kills cancer/tumour
Rotated so that healthy cells receive
limited amount of radiation
[1]
[2]
[1]
[1]
[1]
[1]
[1]
The emission of alpha or beta particles,
or gamma rays from an unstable nucleus
Alpha, beta and gamma
(a) Nucleus
(b) There are 3500 nuclear
disintegrations [1] per minute [1]
(c) It decreases
Answers to include:
(a) gamma – electromagnetic radiation;
alpha – helium nucleus; beta – highspeed electron
(b) alpha = 4, gamma = 0, beta = 1/2000
approx.
(c) alpha = +2, beta = −1, gamma = 0
(d) alpha stopped by paper, beta stopped
by thick (3 mm) aluminium, gamma
penetrates lead
(e) alpha – very ionising, beta –
moderately ionising, gamma – slightly
ionising
(f) alpha – smoke detectors, beta –
tracers/thickness gauges, gamma
tracers/cancer treatment
[1]
[1]
[1]
[2]
[1]
[1]
[1]
[1]
[1]
[1]
[1]
Higher
1
(a) Time taken [1] for count rate to drop
to half its original value [1]
[2]
(b) (i) Correct plot and smooth curve
[2]
Value of count selected [1]; half this
value selected [1]; time between
these two calculated [1]; half-life
equals 15seconds [1]
[4]
(ii) 40 s/25cps
[1]
(iii) Idea that decay is a random
process (NOT incorrect readings)
[1]
2 Tracer 3
[1]
(a) Will allow sufficient time for tests
before it decays
[1]
Beta can penetrate body and be detected
[1]
(b) Tracers 1 and 2 have too short a half-life to
allow tests to be completed. Tracer 1 is alpha and
will not penetrate the body. Tracer 4 has too long a
half-life and patient will be exposed to radiation for
too long [3]
[1]
19 of 41
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OCR GCSE
Additional Science
3
4
(a) Radioactive material
Giving out beta or gamma radiation
(b) Injected into the bloodstream
(c) It can be followed round the patient
using a detector on the outside of the
patient
A higher count rate just before the block
Very low count rate after the blockage as
the radioactive material cannot get past
(d) The advantage is that it saves the
patient from having surgery
(a) gamma radiation [1] as alpha and beta
cannot penetrate that amount of earth [1]
(b) A Geiger counter
(c) At the leak there would be a large
increase in count rate [1] because a lot of
radioactive material has leaked out of the
pipe [1]
[1]
[1]
[1]
Homework Mark Scheme
P4e & P4f Foundation & Higher
3
[2]
[1]
[2]
[1]
[2]
[1]
4
mass number
decrease by 4
number of neutrons
decrease by 2
number of protons
decrease by 2
charge
decrease by 2
(a) (i) 218 is the total number of protons
and neutrons in the nucleus
84 is the number of protons in the
nucleus
(b) 146C
[2]
2
(ii) 21884Po
4
14 N
7
+ 21482Pb
[1]
[1]
[2]
+ 0-1e
[1]
but rays ALWAYS go through tumour
Given in small doses
over several weeks
to allow healthy cells to recover
[1]
[1]
[1]
[1]
20 of 41
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This document may have been altered from the original.
OCR GCSE
Additional Science
Homework Mark Scheme
P4g & P4h Foundation & Higher
P4g Uses of
radioisotopes
4
Foundation
P4h Fission
1
Foundation
2
3
4
5
(a) Background
[1]
(b) Sun, rocks, earth, etc.
[1]
(c) The types of rocks in the ground alter
background radiation; areas with a lot of
granite have high background counts
[2]
Finding underground pipes/tracking
waste/thickness gauges/non-destructive
testing
[4]
Alpha particles ionise air; the electrons
form a small current; the detector
measures these electrons; smoke stops
the electrons and so the alarm goes off. each [1]
(a) Carbon
[1]
(b) Atoms of the same element (same
atomic number) with different numbers
of neutrons (different mass number) each [1]
(a) Beta; alpha stopped by paper; gamma
not affected by paper
each [1]
(b) Count rate will go up
[1]
(c) The count rate will change because of
decay if a short half-life is used; so the
paper will get thinner; which will mean
calibrating the equipment; several times
a day
each [4]
Higher
1
2
3
Industry/hospitals
each [1]
(a) Use a gamma emitter; so it can be
detected on the surface; pour into drain;
follow the radiation on the surface; little
or no radiation past the blockage
each [1]
(b) (i) Beta; alpha stopped by paper;
gamma not affected by paper
each [1]
(ii) count rate will go up
[1]
(iii) the count rate will change because of
decay if a short half-life is used; so the
paper will get thinner; which will mean
calibrating the equipment; several times
a day
each [4]
Amount of carbon-14 constant; living
objects take in carbon-14; when object
dies it stops taking in carbon-14; as the
carbon-14 in the sample decays, the
activity of the sample drops; compare the
activity of living matter and the sample;
leads to fairly accurate date
each [1]
1
2
3
4
5
Alpha radiation ionises air; electrons
move to one plate; current detected;
smoke stops the electron flow; current
stops and alarm goes off
each [1]
Uranium
[2]
Nuclear reaction; heat provided; water
boiled; steam produced; turbine rotated;
generator spins; electricity produced each [1]
(a) A reaction where neutrons from one
atom hit a second atom, causing it to
break up and give out more neutrons
each capable of providing further decay
[2]
(b) The power station is controlled/the
bomb is uncontrolled
[2]
(c) It absorbs neutrons inside the reactor
[2]
Nuclear fission
[1]
For: e.g. include no ash, sulphur dioxide,
etc., many years resources left
[1]
Against: e.g. radioactive waste, long
half-life, potentially dangerous, security,
etc.
[1]
Higher
1
2
3
(a) A neutron; hits a uranium nucleus; is
absorbed; causing it to split; releasing
energy and further neutrons
each [1]
(b) The extra neutrons can cause further
nuclei to split and so on
[1]
(a) Become radioactive
[1]
(b) To prevent public/people outside
being exposed to radiation
[1]
(c) By passing cold gas between the rods
[1]
(d) So that the water is not inside the
reactor, so does not absorb neutrons and
become radioactive
[1]
(e) Rods that control the speed that the
reaction works at
[1]
(f) They are moved into the reactor if it is
too hot or operating too quickly [1] to
absorb the neutrons [1]
[2]
(g) Boron is good at absorbing neutrons
[1]
(h) Ideas that neutrons move quickly; the
uranium absorbs slow neutrons better
than fast ones; the neutrons collide with
the graphite and slow down; allowing
better absorption by the uranium
each [1]
(a) Some of the waste has a very long
half-life
[1]
(b) Approximately 50 years
[1]
21 of 41
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This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
P4a Foundation and Higher
Sparks
1
Solve the clues and fill in the words.
1
2
3
4
5
6
7
2
1
A substance that does not conduct electricity.
2
The charge on an object when it has lost electrons.
3
The rubbing force that strips electrons or a material and makes it charged.
4
The opposite of attract.
5
All charge tries to flow here.
6
Charge that does not flow is called __________ electricity.
7
An electron has a _________ charge.
True or false? Put T or F in the boxes.
[F]
There are two kinds of charge, positive and negative.
A positive charge is when the material has too many electrons.
Like charges attract each other.
You can get an electric shock if you become charged and then become earthed
3
Fill in the gaps using words from the list. Choose six different words from the list.
positive
charge
earth
body
oxygen
electricity
[H]
flammable
Static ________ can become dangerous when large quantities of _______ flow through
your _________ to _________. It can also cause explosions in _________ gases or
vapours with a high concentration of _________.
4
Complete these sentences.
[H]
(a) The chances of receiving an electric shock can de reduced by doing three things:
(i) __________________ (i) __________________ (iii) __________________.
(b) Antistatic sprays, liquids and cloths can reduce the problems of static electricity by
___________________________________________________________________
__________________________________________________________________.
22 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
P4b Foundation and Higher
Uses of electrostatics
1
True or false? Put T or F in the boxes.
[F]
Static electricity can remove smoke from chimneys. The device is called an
electrostatic dust precipitator.
In electrostatic paint spraying the paint and the car are given the same electrostatic
charge.
Two objects in an office that use electrostatics are the photocopier and the coffee
machine.
A defibrillator is the name of the device that paramedics use to restart a patient’s
heart.
2
Draw arrows to connect the start and end of these sentences to make a correct
explanation of how paint spraying a car works.
Paint particles are charged
so that the paint sticks to the car
Car is given the opposite charge
because less paint floats in the air
to the paint
The process is less wasteful
3
so that you get a fine spray
Fill in the gaps using words from the list. Choose seven different words from the list.
heavy
repelled
metal
positive
building materials
attracted
large
[H]
electrostatic
In an _________ dust precipitator there are ________ plates or grids that are connected
to a ________ PD. The dust particles are ________ to the plates. They stick together
until they form _______ particles. When these particles are _______ enough they fall
back down the chimney into containers. The dust is collected and can be used to make
__________.
4
Complete the sentences about heart defibrillators.
(a) In a defibrillator it is important to do two things: ___________________________
__________________________________________________.
(b) When the charge passes through the patient’s body it _______________________
__________________________________________________.
[H]
23 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
P4c Foundation and Higher
Safe electrics
1
Solve the clues and fill in the crossword.
[F]
1
2
3
4
5
6
7
2
1
The earth wire in a plug is yellow and ________.
2
The wire that carries the high voltage.
3
A material that allows electric current to flow through it.
4
The wire that is missing from a double insulated device.
5
A variable resistor controls this.
6
Resistance is calculated as _______ / current.
7
The colour of the live wire in a plug.
True or false? Put T or F in the boxes.
[F]
An earthed conductor can never become live.
A fuse melts if the current becomes too large.
For a given resistor, if the potential difference increases, then the current
decreases.
The casing of a double insulated appliance is made of an insulator
3
Fill in the gaps using words from the list. Choose five different words from the list.
overheat
protect
isotope
current
fire
melt
[H]
current
A fuse wire is put into a circuit to ______ an appliance. If the appliance develops a
fault, too large a ______ causes the fuse to ______. This prevents the flow of ______.
This means that the flex won’t ______ and cause a ______ and the appliance won’t be
damaged further.
4
Work out the following calculations.
(a) If the current in a circuit is 2A and the voltage is 100V, what is the resistance?
__________________________________________
(b) For a resistance of 20 ohms, what current do you get from a voltage of 220 V?
[H
__________________________________________
24 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
P4d Foundation and Higher
Ultrasound
1
True or false? Put T or F in the boxes.
[F]
The upper threshold of human hearing is 12,000 Hz.
The frequency of ultrasound is higher than the upper threshold of human hearing.
Ultrasound is used in hospitals for taking X-rays of broken bones.
Ultrasound is used in hospitals to measure the speed of blood flow in the body.
Ultrasound is used in hospitals for breaking down kidney stones.
2
For each word put the letter of the correct meaning
Word
[F]
Answer
Meaning
Amplitude
(a) The area when the particles
are closest together.
Wavelength
(b) The number of waves
passing a point each second.
Frequency
(c) The maximum movement of
particles from their normal
position when a wave passes.
Compression
(d) The area where the particles
are furthest apart.
Rarefaction
(e) The distance between two
compressions.
3
Fill in the gaps using words from the list. Choose three different words from the list.
wave
transverse
right angles
wavelength
[H]
longitudinal
In a ________ wave the particles move parallel to the direction that the wave is
moving. In a ________ wave the particles move at ________ to the direction the wave
is moving. Sound is an example of a ________ wave.
25 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
P4e Foundation and Higher
Treatment
1
Solve the clues and fill in the crossword
[F]
1
2
3
4
5
2
1
The person who takes X-rays in a hospital.
2
Nuclear __________ is used to sterilise hospital equipment.
3
X-rays and gamma rays are both ______________ radiation.
4
Gamma rays are focused on this to kill the cells in cancer treatment.
5
These are used to look at broken bones in the body.
True or false? Put T or F in the boxes.
[F]
Gamma rays are used to treat cancer in hospitals.
Beta radiation and gamma radiation can both pass through the skin.
X-rays and gamma rays have very different wavelengths.
Beat and gamma radiation can be used as tracers in hospitals
3
Fill in the gaps using words from the list. Choose eight different words from the list.
leak
gas
detector
gamma
liquid
isotope
beta
spreads
[H]
alpha
blockage
A medical physicist can use ______ radiation or ______ radiation as a tracer. The
patient is given the beta or gamma emitter and it ______ through the body. The
physicist uses a ______ to follow it outside the body to see if there is a ______ or a
______. The tracer can be either a ______ or a ______.
4
Complete these sentences:
(a) To treat cancer a wide beam of gamma rays is focussed on the tumour and the
beam is rotated around the patient with the tumour at the centre so that __________
______________________________________________________.
(b) X-rays are made by ______________________________________.
[H]
(c) The main differences between X-rays and gamma rays are ___________________
______________________________________________________.
26 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: Answers
P4f Foundation and Higher
What is radioactivity
1
True or false? Put T or F in the boxes.
[F]
Radiation comes from the nucleus of an atom.
Radioactivity from a material increases with time.
An alpha particle is like a helium nucleus.
A beta particle is like a helium nucleus.
2
[H]
A
Mass number decreases by 4
B
Mass number is unchanged
C
Nucleus has one less proton
D
Nucleus has two fewer protons
E
Nucleus has one more proton
F
Nucleus has two fewer neutrons
G
Atomic number increases by one
H
Atomic number decreases by two
(a) From the list choose the letters that describe what happens to the nucleus of an
atom when it emits an alpha particle. __________.
(b) From the list choose the letters that describe what happens to the nucleus of an
atom when it emits a beta particle. __________.
3
Fill in the gaps using words from the list. Choose four different words from the list.
electron
isotope
decays
radiation
gamma
helium
[F]
beta
A radioactive substance ______ naturally. It gives out ______ in the form of alpha,
______ and ______ radiation. An alpha particle is like a ______ nucleus. A beta
particle is like an ______.
4
Balance these equations to show what new element is formed:
(a) X92235
=
Y+α
__________.
(b) X92235
=
Y+β
__________.
[H]
27 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
P4g Foundation and Higher
Uses of radioisotopes
1
Solve the clues and complete the crossword below to work out the word in the shaded
squares
[F]
1
2
3
4
5
6
1
Industry uses radioactive materials to track the dispersal of this.
2
Radioactive __________ is used to work out the age of old materials such as
Egyptian mummies or wooden objects.
2
3
Tracers can be used to find leaks and _______ in underground pipes.
4
The radiation all around us is called _____________ radiation.
5
Tracers are also used to find the route or location of underground ________.
6
Radioactivity can also be used to date these.
True or false? Put T or F in the boxes.
[F]
Radioactive alpha sources are used in smoke detectors.
Background radiation comes from rocks and soil.
Background radiation is decreasing all the time.
Background radiation also comes from cosmic rays.
3
Fill in the gaps using words from the list.
rocks
carbon 12
carbon 14
isotope
[H]
date
metal
protons
To find out the age of an Egyptian mummy you need to know the amount of
radioactive _______ in it as well as the amount of non-radioactive _______. The ratio
of _______ to _______ will decrease over time. From this you can work out the
_______ of the object. This method will not work for _______ or _______.
4
Complete these sentences:
[H]
(a) When smoke gets into a smoke detector the alpha particles ___________________
__________________________________________________________________.
(b) To work out the date of rocks you need to know ____________________________
__________________________________________________________________.
28 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz
P4h Foundation and Higher
Fission
1
True or false? Put T or F in the boxes.
[F]
Nuclear power stations use uranium as fuel.
The decay of uranium can be described as a chain reaction.
A nuclear bomb is a chain reaction that has gone out of control.
Materials can be made radioactive by putting them into a nuclear reactor.
2
The table below shows the stages in generating electricity in a nuclear power station.
[F]
They are in the wrong order. What is the correct order? __________.
A
The steam turns a turbine
B
The uranium undergoes nuclear reactions in the power station to
create heat
3
C
The turbine turns a generator
D
The heat is used to heat water into steam
E
The generator generates electricity that is sent to consumers
Fill in the gaps using words from the list.
electrons
control rods
isotopes
uranium
[H]
neutrons
fission
chain reaction
When a uranium atom splits this is called _________. Several _________ are given out
each time an atom splits. These _________ cause other _________ atoms to split. This
is called a _________. To stop nuclear reactors going out of control, scientists put
_________ into the reactor. These absorb the excess _________ but allow enough
_________ to hit new _________ atoms to keep the reaction going.
4
Complete these sentences.
(a) Materials can become radioactive when they absorb extra neutrons because
___________________________________________________________________
____________________________________.
(b) Nuclear fission can produce radioactive waste. The problem with radioactive waste
is that _____________________________________________________________
____________________________________.
29 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: Answers
P4a Foundation and Higher
Sparks
1
Solve the clues and fill in the words.
1
6
2
3
I
N
S
U
L
A
T
O
R
2
3
P
O
S
I
T
I
V
E
F
R
I
C
T
I
O
N
4
R
E
P
E
5
E
A
R
T
H
I
V
E
S
T
A
T
I
C
7
N
E
G
A
T
L
1
A substance that does not conduct electricity.
2
The charge on an object when it has lost electrons.
3
The rubbing force that strips electrons or a material and makes it charged.
4
The opposite of attract.
5
All charge tries to flow here.
6
Charge that does not flow is called ___ electricity.
7
An electron has a ____ charge.
True or false? Put T or F in the boxes.
[F]
There are two kinds of charge, positive and negative.
T
A positive charge is when the material has too many electrons.
F
Like charges attract each other.
F
You can get an electric shock if you become charged and then become earthed
T
Fill in the gaps using words from the list. Choose six different words from the list.
positive
charge
earth
body
oxygen
electricity
[H]
flammable
Static electricity can become dangerous when large quantities of charge flow through
your body to earth. It can also cause explosions in flammable gases or vapours with a
high concentration of oxygen.
4
Complete these sentences.
[H]
(a) The chances of receiving an electric shock can de reduced by doing three things:
(i) correct earthing (i) using insulating mats (iii) using shoes with insulating holes.
(b) Antistatic sprays, liquids and cloths can reduce the problems of static electricity by
making the materials more conducting so that electrostatic charge cannot build up
on them.
30 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: Answers
P4b Foundation and Higher
Uses of electrostatics
1
2
True or false? Put T or F in the boxes.
[F]
Static electricity can remove smoke from chimneys. The device is called an
electrostatic dust precipitator.
T
In electrostatic paint spraying the paint and the car are given the same electrostatic
charge.
F
Two objects in an office that use electrostatics are the photocopier and the coffee
machine.
F
A defibrillator is the name of the device that paramedics use to restart a patient’s
heart.
T
Draw arrows to connect the start and end of these sentences to make a correct
explanation of how paint spraying a car works.
Paint particles are charged
so that the paint sticks to the car
Car is given the opposite charge
because less paint floats in the air
to the paint
The process is less wasteful
3
so that you get a fine spray
Fill in the gaps using words from the list. Choose seven different words from the list.
heavy
repelled
metal
positive
building materials
attracted
large
[H]
electrostatic
In an electrostatic dust precipitator there are metal plates or grids that are connected to
a positive PD. The dust particles are attracted to the plates. They stick together until
they form large particles. When these particles are heavy enough they fall back down
the chimney into containers. The dust is collected and can be used to make building
materials.
4
Complete the sentences about heart defibrillators.
(a) In a defibrillator it is important to do two things: make good electrical contact with
the patient’s body and take care not to shock the operator .
(b) When the charge passes through the patient’s body it makes the patient’s heart
contract and start beating again.
[H]
31 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: Answers
P4c Foundation and Higher
Safe electrics
1
Solve the clues and fill in the crossword.
1
3
6
2
3
G
R
E
E
N
2
L
I
V
E
C
O
N
D
U
C
4
5
E
A
R
T
H
C
U
R
R
V
O
L
T
7
B
[F]
T
O
E
N
T
A
G
E
L
U
E
R
1
The earth wire in a plug is yellow and ________.
2
The wire that carries the high voltage.
3
A material that allows electric current to flow through it.
4
The wire that is missing from a double insulated device.
5
A variable resistor controls this.
6
Resistance is calculated as _______ / current.
7
The colour of the live wire in a plug.
True or false? Put T or F in the boxes.
[F]
An earthed conductor can never become live.
T
A fuse melts if the current becomes too large.
T
For a given resistor, if the potential difference increases, then the current
decreases.
F
The casing of a double insulated appliance is made of an insulator
T
Fill in the gaps using words from the list. Choose five different words from the list.
overheat
protect
isotope
current
fire
melt
[H]
current
A fuse wire is put into a circuit to protect an appliance. If the appliance develops a
fault, too large a current causes the fuse to melt. This prevents the flow of current.
This means that the flex won’t overheat and cause a fire and the appliance won’t be
damaged further.
4
Work out the following calculations.
(a) If the current in a circuit is 2A and the voltage is 100V, what is the resistance?
Resistance = voltage/current = 100/2 = 50 ohms
(b) For a resistance of 20 ohms, what current do you get from a voltage of 220 V?
[H
Current = voltage/resistance = 220/20 = 11 amps
32 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: Answers
P4d Foundation and Higher
Ultrasound
1
2
True or false? Put T or F in the boxes.
[F]
The upper threshold of human hearing is 12,000 Hz.
F
The frequency of ultrasound is higher than the upper threshold of human hearing.
T
Ultrasound is used in hospitals for taking X-rays of broken bones.
F
Ultrasound is used in hospitals to measure the speed of blood flow in the body.
T
Ultrasound is used in hospitals for breaking down kidney stones.
T
For each word put the letter of the correct meaning
[F]
Word
Answer
Meaning
Amplitude
C
(a) The area when the particles
are closest together.
Wavelength
E
(b) The number of waves
passing a point each second.
Frequency
B
(c) The maximum movement of
particles from their normal
position when a wave passes.
Compression
A
(d) The area where the particles
are furthest apart.
Rarefaction
D
(e) The distance between two
compressions.
3
Fill in the gaps using words from the list. Choose three different words from the list.
wave
transverse
right angles
wavelength
[H]
longitudinal
In a longitudinal wave the particles move parallel to the direction that the wave is
moving. In a transverse wave the particles move at right angles to the direction the
wave is moving. Sound is an example of a longitudinal wave.
33 of 41
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OCR GCSE
Additional Science
Self-assessment quiz: Answers
P4e Foundation and Higher
Treatment
1
Solve the clues and fill in the crossword
3
2
3
E
1
R
A
D
I
O
G
R
2
R
A
D
I
A
L
E
C
T
R
O
M
4
5
T
U
M
O
X
R
A
Y
[F]
A
P
H
T
I
O
N
A
G
N
E
U
R
E
R
T
I
C
1
The person who takes X-rays in a hospital.
2
Nuclear __________ is used to sterilise hospital equipment.
3
X-rays and gamma rays are both ______________ radiation.
4
Gamma rays are focused on this to kill the cells in cancer treatment.
5
These are used to look at broken bones in the body.
True or false? Put T or F in the boxes.
[F]
Gamma rays are used to treat cancer in hospitals.
T
Beta radiation and gamma radiation can both pass through the skin.
T
X-rays and gamma rays have very different wavelengths.
F
Beat and gamma radiation can be used as tracers in hospitals
T
Fill in the gaps using words from the list. Choose eight different words from the list.
leak
gas
detector
gamma
liquid
isotope
beta
spreads
[H]
alpha
blockage
A medical physicist can use beta radiation or gamma radiation as a tracer. The patient is
given the beta or gamma emitter and it spreads through the body. The physicist uses a
detector to follow it outside the body to see if there is a leak or a blockage. The tracer
can be either a liquid or a gas.
4
Complete these sentences:
(a) To treat cancer a wide beam of gamma rays is focussed on the tumour and the
beam is rotated around the patient with the tumour at the centre so that there is
limited damage to the non-cancerous cells.
(b) X-rays are made by firing high-speed electrons at a metal target.
[H]
(c) The main differences between X-rays and gamma rays are the way they are made,
where they come from and how easily they are controlled.
34 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: Answers
P4f Foundation and Higher
What is radioactivity
1
True or false? Put T or F in the boxes.
[F]
Radiation comes from the nucleus of an atom.
T
Radioactivity from a material increases with time.
F
An alpha particle is like a helium nucleus.
T
A beta particle is like a helium nucleus.
F
2
[H]
A
Mass number decreases by 4
B
Mass number is unchanged
C
Nucleus has one less proton
D
Nucleus has two fewer protons
E
Nucleus has one more proton
F
Nucleus has two fewer neutrons
G
Atomic number increases by one
H
Atomic number decreases by two
(a) From the list choose the letters that describe what happens to the nucleus of an
atom when it emits an alpha particle. A, D, F, H.
(b) From the list choose the letters that describe what happens to the nucleus of an
atom when it emits a beta particle. B, E, G.
3
Fill in the gaps using words from the list. Choose four different words from the list.
electron
isotope
decays
radiation
gamma
helium
[F]
beta
A radioactive substance decays naturally. It gives out radiation in the form of alpha,
beta and gamma radiation. An alpha particle is like a helium nucleus. A beta particle is
like an electron.
4
Balance these equations to show what new element is formed:
(a) X92235
=
Y+α
= Y90231
(b) X92235
=
Y+β
= Y93235
[H]
35 of 41
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This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: Answers
P4g Foundation and Higher
Uses of radioisotopes
1
Solve the clues and complete the crossword below to work out the word in the shaded
squares
[F]
1
3
B
L
5
W A
S
T
E
2
C
A
R
B
O
N
O
C
K
A
G
E
S
4
B
A
C
K
G
R
O
P
I
P
E
S
6
R
O
C
K
S
U
N
D
1
Industry uses radioactive materials to track the dispersal of this.
2
Radioactive __________ is used to work out the age of old materials such as
Egyptian mummies or wooden objects.
2
3
3
Tracers can be used to find leaks and _______ in underground pipes.
4
The radiation all around us is called _____________ radiation.
5
Tracers are also used to find the route or location of underground ________.
6
Radioactivity can also be used to date these.
True or false? Put T or F in the boxes.
[F]
Radioactive alpha sources are used in smoke detectors.
T
Background radiation comes from rocks and soil.
T
Background radiation is decreasing all the time.
F
Background radiation also comes from cosmic rays.
T
Fill in the gaps using words from the list.
rocks
carbon 12
carbon 14
isotope
[H]
date
metal
protons
To find out the age of an Egyptian mummy you need to know the amount of
radioactive carbon 14 in it as well as the amount of non-radioactive carbon 12. The
ratio of carbon 14 to carbon 12 will decrease over time. From this you can work out the
date of the object. This method will not work for rocks or metal.
4
Complete these sentences:
[H]
(a) When smoke gets into a smoke detector the alpha particles are no longer detected
(because the smoke prevents them getting through) so the alarm sounds .
(b) To work out the date of rocks you need to know the ratio of uranium to lead in
the rocks.
36 of 41
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This document may have been altered from the original.
OCR GCSE
Additional Science
Self-assessment quiz: Answers
P4h Foundation and Higher
Fission
1
2
True or false? Put T or F in the boxes.
[F]
Nuclear power stations use uranium as fuel.
T
The decay of uranium can be described as a chain reaction.
T
A nuclear bomb is a chain reaction that has gone out of control.
T
Materials can be made radioactive by putting them into a nuclear reactor.
T
The table below shows the stages in generating electricity in a nuclear power station.
[F]
They are in the wrong order. What is the correct order? B, D, A, C, E.
A
The steam turns a turbine
B
The uranium undergoes nuclear reactions in the power station to
create heat
3
C
The turbine turns a generator
D
The heat is used to heat water into steam
E
The generator generates electricity that is sent to consumers
Fill in the gaps using words from the list.
electrons
control rods
isotopes
uranium
[H]
neutrons
fission
chain reaction
When a uranium atom splits this is called fission. Several neutrons are given out each
time an atom splits. These neutrons cause other uranium atoms to split. This is called a
chain reaction. To stop nuclear reactors going out of control, scientists put control rods
into the reactor. These absorb the excess neutrons but allow enough neutrons to hit new
uranium atoms to keep the reaction going.
4
Complete these sentences.
(a) Materials can become radioactive when they absorb extra neutrons because
the extra neutrons get into the nucleus and it is now too big to be stable so it
breaks apart.
(b) Nuclear fission can produce radioactive waste. The problem with radioactive waste
is that it is toxic to humans and it takes a long time to become safe. This means we
have to store it safely for a long time.
37 of 41
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This document may have been altered from the original.
OCR GCSE
Additional Science
Student checklist P4
P4 – Radiation for life
Tick () column: A when you have covered the
statement in class.
Tick () column B if you need to do more work on it.
Tick () column C when you are confident you can
answer any questions on it.
In your revision for your end-of-block test or final
examinations, concentrate most time on those
statements not ticked.
Statements in bold can only appear on the Higher
tier paper.
I can:
1
A
B
C
Describe how to charge an insulating material by rubbing it with a cloth
State that the two types of charge are positive and negative
Describe that some charged materials attract others such as small pieces of
paper to a comb
State that like charges repel and unlike charges attract
State and recognise that the transfer of electrons cause electrostatic effects
Describe how you can get a shock from synthetic clothing
Describe how you can get a shock by earthing yourself after becoming
charged
Explain how static electricity can be dangerous in explosive atmosphere
such as re-fuelling planes or where large currents are involved eg lightning
Describe how static electricity can be a nuisance eg dust attracted to
televisions, clothes clinging
Describe static electricity in terms of movement of electrons
eg positive = loss, negative = gain
Explain how the chance of shock can be reduced by earthing, insulating
mats, insulated footwear
Explain why lorries containing inflammable gases/liquids/powders,
should be earthed before unloading
Explain how antistatic materials reduce the problem of
static electricity
2
Recognise ways in which static electricity can be useful eg defibrillators /
photocopiers / printers / dust extractors / paint spraying
Describe and explain how static electricity can be useful in a defibrillator
Describe and explain how electrostatic dust precipitators remove smoke and
dust from chimneys
Describe and explain how static electricity is used in paint spraying
3
Recognise that a complete circuit is needed for current to flow
State that an earthed conductor cannot become live
Explain the behaviour of simple circuits in terms of charge
Describe how resistors / variable resistors can change the current in a circuit
38 of 41
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OCR GCSE
Additional Science
Student checklist P4
I can:
A
B
C
Describe the relationship between current, potential difference and
resistance
Use the equation Resistance = voltage / current
to calculate resistance, voltage and current
State the colour coding for live, neutral and earth wires
Describe and Explain the function of live neutral and earth wires
Describe the reason for using fuses in circuits
Explain how a wire fuse works
Describe and explain why double insulated appliances do not need earthing
Explain how a wire fuse protects an appliance
Explain the reasons for the use of fuses and circuit breakers
Explain how a wire fuse and earthing protects people
4
State and recognise that ultrasound is a longitudinal wave
Recognise features of a longitudinal wave eg amplitude, wavelength,
frequency, compression and rarefaction
Describe the features of a longitudinal wave
State the meaning of ultrasound
Describe the motion of particles in a longitudinal wave
State and describe the uses of ultrasound in medicine
Explain how ultrasound is used in body scans / breaking down kidney
stones
Explain the reasons for using ultrasound in preference
to X-rays
5
State that nuclear radiation is used in medicine
State that X-rays and gamma rays are electromagnetic waves
State that only beta and gamma radiation can pass through skin
Explain that gamma rays are given out by the nucleus of certain
radioactive materials
Explain that X-rays are made by firing high speed electrons at metal
targets
Explain that X-rays can be controlled more easily than
gamma rays
State that radiographers take X-rays in hospitals
State that nuclear radiation damages cells
39 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Student checklist P4
I can:
A
B
C
State that nuclear radiation can be used to sterilize hospital equipment
State that gamma rays can be used to treat cancer
Describe how gamma and beta emitters can be used as tracers
Describe how gamma rays and X-rays have similar wavelengths but are
produced in different ways
Explain how radioactive sources are used to treat cancer
Explain how radioactive sources can be used as tracers
6
State that radioactivity is measured by the number of nuclear decays per
second
Describe that radioactive substances give out nuclear radiation as alpha beta
or gamma rays
Recognise that radioactivity decreases with time
Describe radioactivity as coming from the nucleus
State that an alpha particle is a helium nucleus
State that a beta particle is a fast moving electron
Explain and use the idea of half life
Interpret graphical and numerical data on radioactive
decay
Describe what happens to a nucleus when an alpha particle is emitted
Describe what happens to a nucleus when a beta particle is emitted
Construct balanced nuclear equations to represent alpha and beta
decay
7
Describe background radiation as radiation in the environment that is always
present
State that background radiation comes from rocks/soil/cosmic rays
Explain that background radiation comes from waste products and man
made sources such as industry and hospitals
State that radioisotopes are used in hospitals and industry
Give examples of uses of tracers
Describe how tracers are used to track underground pipes
Describe how a smoke detector with an alpha source works
Recall that radioactivity can be used to date rocks and measurement of
radioactive carbon can find the date of old materials
Explain how the radioactive dating of rocks uses the radio of uranium
to lead
40 of 41
© Harcourt Education 2006, OCR Gateway Science
This document may have been altered from the original.
OCR GCSE
Additional Science
Student checklist P4
I can:
A
B
C
Explain how measurement of radioactive carbon can give the age of
different materials
8
Recognise that nuclear power stations use uranium as fuel
Describe the main stages in the production of electricity
Describe how electricity is generated in a nuclear power station
Describe the process in which a uranium atom splits, releasing energy
State that the decay of uranium can be a chain reaction
Describe a nuclear bomb as a chain reaction out of control
State that materials can be made radioactive by putting them in a nuclear
reactor
Describe the process giving out energy in a nuclear reactor as nuclear
fission
State that nuclear fission produces radioactive waste
Describe how materials become radioactive when they absorb neutrons
Explain what is meant by a chain reaction
Explain how scientist control nuclear reactions in a nuclear reactor by
using rods to absorb spare neutrons
41 of 41
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