Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
GET SOME PRACTICE
PD4 Using electricity
Current, voltage and power
1
a.c. – Alternating current
d.c. – Direct current
2
Marks awarded for:
In d.c. electrons always flow in one direction
In a.c. the direction of flow alternates
3
12 V = 12 J/C
12 J/C 8 C = 96 J
4
The ammeter should be connected in series with the bulb
The voltmeter should be connected in parallel, across the bulb
5
Clockwise from top: V = 9 V, I = 2 A, I = 0.5 A, V = 6 V
6
Ions
7
P = V I = 12 V 2.5 A = 30 W
Resistance
1
Moving the connector so the resistance wire is longer will
increase the resistance and therefore decrease the current.
A smaller resistance (shorter resistance wire) will increase the
current
2
It decreases
3
The resistance would increase
4
a Constant resistance; ohmic resistor
b Resistance increases; filament lamp
c Resistance decreases; thermistor
2
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Static electricity
1
Missing words should be in the following order:
charge, negative, negative, protons, electrons, attract
2
a Negative
b A fine, even coat is obtained because the droplets are the
same charge and repel each other
The paint is attracted to the object, even to awkward areas
3
Friction could cause a charge to build up, which creates a
spark that could ignite the fuel
PD5 Physics at work
Energy and power
1
a i
A car moving at 20 m/s
b ii A bus moving at 15 m/s
2
a i
A car on the top of a multistorey car park
b ii A bus at the top of the same hill
Energy
3
Time
4
C
5
W = Fs = 400 N 3 m = 1200 J
6
a W = Fs = 600 N 40 m = 24 000 J
b 24 000 J
c P = W t (5 min = 300 seconds)
P = 24 000 J 300 seconds = 80 W
7
a 100 J
b 10 %
c Heat (thermal) energy
3
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Electricity from producer to consumer
1
Move the wire in and out of the coil
The direction of the needle is determined by the direction of
current flow, which in turn is determined by the direction of
movement of the magnet
2
Marks awarded for:
The coal is burned to release heat energy
The heat is used to boil water to produce high pressure
steam
The high pressure steam turns a turbine, which turns a
generator to produce electricity
3
It connects power stations to each other, and to houses, offices
etc. to provide a constant supply of electricity
4
a Step-down
b Turns ratio = voltage ratio
Voltage is stepped down to
1
——
200
the original value
So, number of turns in secondary coil is 2000 200 =
100 turns
5
a To provide a magnetic field
b To increase the effect of the magnetic field produced by the
current
c To provide a connection whilst still allowing the
commutator to rotate – they aren’t fixed to a particular side
d This ensures that the current (and therefore the force felt) is
always in the same direction as the armature turns
Communicating with physics
1
Light is shone down the cable
The angle of incidence is greater than the critical angle, so the
light is totally internally reflected along the cable
(A diagram showing this can achieve both marks)
4
Co-ordinated Science 2
2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Two examples from:
Microwaves and radio waves can be used for long distance
communication, for example for TV signals, radio signals or
mobile phones
Infrared can be used for short-range communication, such
as that between a TV and its remote control
Infrared pulses can be sent along fibre optic cables to allow
communication between computers
3
Different layers of the atmosphere have different densities
This causes the waves to refract and change direction
This can result in signal loss
4
a A dimmer switch; a clock with hands
b A normal light switch; a digital watch
PD6 Earth, space and radiation
Getting up
1
C
2
acceleration = change in velocity time taken = 50 5 = 10 m/s2
3
A, B, C, E and F should all be circled
4
700 N; gravitational
Coming down
1
a w = mg = 65 kg 10 N/kg = 650 N
b w = mg = 65 kg 1.6 N/kg = 104 N
2
65 kg (mass doesn’t change)
3
A is on the Earth as the object reaches a terminal velocity,
implying an atmosphere
B has a constant acceleration, implying no atmosphere
4
a Weight and air resistance
b They are equal
5
Gravity
5
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Inside the atom
1
Name
Description
Charge
Alpha
Helium nucleus Positive
particle (2 protons and
2 neutrons)
Beta
Fast moving
particle electrons
Range in air Stopped by
A few
centimetres
(up to
10 cm)
Paper, skin
Negative Up to about A few
millimetres
1 metre
of aluminium
Gamma Electromagnetic No
ray
wave
charge
Unlimited
Several
metres of
concrete
2
A charged atom
3
They can destroy or damage them, leading to cancer
4
Smoke detectors
5
Two from: radioactive rocks and soil; radioactive gases in the
atmosphere; cosmic rays
6
A line of best fit should be drawn through the points
It takes about 40 minutes for the activity to drop to about half
of the initial value, so the half life is approximately
40 minutes
Beyond the Earth
1
A star is much more massive than a bulb
2
a C, E, D, B, F, A
b Neutron star, black hole
3
The Big Bang
4
Three from:
No surface water (a high percentage is needed)
Temperature is about 450°C too high
No oxygen in the atmosphere
The pressure is almost 100 times greater than is suitable
6
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
CD4 Carbon chemistry
Recognising alkanes and alkenes
1
a C2H6
b CnH2n+2
c i
Propene
ii Propane and ethane
d Marks awarded for:
Add a few drops of bromine water and stir
Propene will decolourise the bromine water from
orange-brown to colourless
Propane will remain orange-brown
e
H
f
H
H
C
C
Br
Br
H
ethene + hydrogen → ethane
(1 mark for reactants, 1 mark for product)
Cracking
1
a Petrol
b Kerosene or naphtha
c Marks awarded for:
Kerosene is cracked into a smaller, more useful alkane
(octane)
A small alkene (ethene) is also produced
Conditions required – high temperatures, a catalyst
d Any smaller alkane
An alkene (that has the correct number of carbons and
hydrogens to add up to 9 carbons and 20 hydrogens when
added to the alkane above)
7
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Polymerisation and plastics
1
a High pressure, a catalyst
b
H
H
C
C
H
H
c Polyethene
d Two from:
Non-toxic – to avoid contamination of drink
Easy to mould – enables a sturdy cup shape
A good insulator – to keep drinks hot
A high melting point – so the cup doesn’t melt
Covalent bonding
1
a A chemical bond formed between two atoms by sharing
electrons
b
Hydrogen
Carbon
c
(1 mark for correct carbon molecule, 4 marks for correct
hydrogen molecules)
d Methane has a low boiling point
Methane does not conduct electricity
8
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Allotropes of carbon
1
a Substances that are made up of the same element, but are
in a different form
b Buckminsterfullerene
c Covalent
d Property, one from: slippery layers, high melting point,
conducts electricity
Use, one from: lubricant for machine parts, “lead” in pencils
e Graphite has delocalised electrons
f Marks awarded for:
Diamond has all its electrons bound in covalent bonds;
they are fixed
In graphite, the delocalised (free) electrons are able to
move between layers
This allows the conduction of electricity
CD5 Chemical economics
Chemical quantities
1
H2SO4 + 2NaOH → Na2SO4 + 2H2O
142
H2SO4 + CuO → H2O + CuSO4
H2SO4 – 98
CuO – 80
H2O – 18
CuSO4 – 160
e 40 g
f No. moles copper = 96 64 = 1.5
No. moles oxygen = 12 16 = 0.75
Formula = Cu2O
(1 mark for calculating the moles, 1 mark for the formula)
a
b
c
d
Making ammonia
1
a 2N2 + 3H2 → NH3 (1 mark for formulae, 1 mark for balancing)
b The air
c i High temperature (450°C), high pressure, iron catalyst
ii High pressure – increases the yield
High temperature – decreases the yield
Catalyst – speeds up the rate of the reaction
9
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Industrial processes
1
a Two from:
Cost of electricity, gas or water
Transport of products
Maintenance of apparatus
Cost of the building
b Marks awarded for:
A low temperature increases the % yield
A high pressure increases the % yield
The catalyst increases the rate of the reaction but does
not increase the % yield
At low temperatures the rate of reaction is so slow, it is
more economical to operate at a higher temperature that
still gives a sufficiently high yield
Neutralisation reactions
1
a Marks awarded for:
Add universal indicator to each solution
Observe the colour change in each case
Match the colours to the colour chart for universal
indicator (pH of 1–6 is an acid; pH of 8–14 is
an alkali)
b Neutralisation reaction
c Ammonium nitrate
d H2SO4 + 2KOH → K2SO4 + 2H2O (1 mark for products,
1 mark for reactants, 1 mark for balancing)
e H+ + OH– → H2O
Fertilisers
1
a Nitrogen, phosphorus, potassium
2
Nitric acid or sulphuric acid
3
Marks awarded for:
Fertilisers cause excessive algae growth in rivers
The algae cover the surface and prevent light getting into
the water
10
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Plants and the algae die and aerobic bacteria break down
the dead plant matter, consuming lots of oxygen in the
process
Fish and wildlife in the river die from a lack of oxygen
CD6 The Periodic Table
The structure of the atom
1
a
Name
Relative mass
Relative charge
Proton
1
+1
Neutron
1
0
Electron
0.0005
–1
b 17 protons; 18 neutrons
c Isotopes
d Atomic (or proton)
e 2,8,7
Groups and periods
1
Second group – 2 electrons in the outer shell
Third period – 3 shells are filled or partially filled with
electrons
2
Group 8
A closer look at Groups 1, 7 and 8
1
a Group 1
b The atom has 1 electron present in its outer shell, which is
unfavourable in terms of energy/stability
c Hydrogen
2
Marks awarded for:
Apparatus: Bunsen burner, flame testing wire
Method: clean wire with concentrated acid, dip wire into
solid compound, hold in hottest part of roaring flame
If lithium is present, the flame colour observed will be red
11
Co-ordinated Science 2
Year 11 Collins Student Support Materials
3
ISBN 0 00 715667 7
a Any 1 from:
Chlorine – sterilises water
Bromine – used in photography
Iodine – sterilises skin
b chlorine + sodium iodide → sodium chloride + iodine
c Cl2 + 2NaI → 2NaCl + I2
4
a Marks awarded for:
Noble gases have a full outer shell of electrons and so
are unreactive
All noble gases are colourless
Helium is used in balloons – it is less dense than air
All noble gases can be used in lighting as they are
unreactive
b They already have full outer shells so they do not need to
lose or gain electrons to form ions
Ions and bonding
1
a A chemical bond formed when electrons are transferred
from one atom to another
b
Mg
O
Mg2+
c Two from:
High melting point solids
Will dissolve in water
Will conduct electricity if molten or dissolved
Transition metals
1
a One from:
Copper sulphate – blue
Copper carbonate – green
Copper oxide – black
12
O2–
Co-ordinated Science 2
2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
a copper carbonate → copper oxide + carbon dioxide
b CuCO3 → CuO + CO2
3
a A blue coloured, gelatinous precipitate
b Precipitation/ionic reaction
c Cu2+ + 2OH– → Cu(OH)2
BD4 Variation, inheritance and
evolution
Characteristics and why they vary
1
a A difference in their environment, for example Alice’s
poppies could be exposed to more light
b A change in a gene that causes a different characteristic to
develop
One cause from: UV light, X-rays, some chemicals
c i
Sickle cell anaemia and cystic fibrosis should be
circled
ii Microbes (viruses, bacteria)
d Marks awarded for, for example:
Environmental factors such as training, a good coach,
good training facilities, diet
Genetic factors, for example sprinters have genes that
result in ‘fast-twitch’, powerful muscles, long-distance
runners have genes that result in ‘slow-twitch’ muscles
with stamina, long jumpers have genes that result in
long legs
Genes and chromosomes
1
a Gene
b Nucleus
c DNA
2
Sex cells, sperm and eggs, which join at fertilisation
3
a i
38
ii 19
13
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
b Marks awarded for:
In each type of cell, only a few genes are ‘switched on’,
most are not active
The genes that are ‘switched on’ differ in each cell
type
In red blood cells the gene to produce haemoglobin is
‘switched on’ but not the gene for contracting and
relaxing
Passing on genetic information
1
a, b, c
Male parent
12
Female parent
(millions of cells)
(millions of cells)
12
* meiosis
* meiosis
6
6
Sperm
Egg
}
gametes +
* fertilisation
zygote +
12
*
mitosis
12
12
Embryo (a few cells)
12
*
mitosis
12
Adult
(millions of
cells)
d Marks awarded for:
Its genes have come from two different individuals (half
from each)
So, its combination of genes will be different from each
parent
Gametes produced by each individual have different
combinations of genes, so brothers and sisters will have
different combinations of genes
14
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Evolution
1
a Only the hard parts of an organism are fossilised, for
example skeletons and teeth, not skin, muscle and other
soft organs
b Two from:
Most individuals are not fossilised when they die, the
conditions needed for fossilisation are not present
Many fossils are yet to be found
Many fossils have been destroyed
c The fossil shows characteristics of both birds and reptiles
(feathers and a reptile-like tail)
d Marks awarded for:
No, it is only one piece of evidence
There could be other explanations for this evidence
Proof requires many pieces of evidence
Improving the genome
1
a Marks awarded for:
It will enable her to produce a higher yield/better quality
of peas
She will therefore be paid a better price
b X because it has bigger pods (and so more peas in each pod)
Y because it has a large number of pea pods
c Marks awarded for:
From the offspring of breeding X and Y she should
choose the best plants (most/biggest pods)
She should breed these offspring together
She should then choose the best of their offspring to
breed together and keep repeating these steps
2
a It will be reduced; other pea plants with different genes will no
longer be grown and so there will be a smaller variety of genes
b If the environment changes (e.g. colder winters, a new
disease) a smaller gene pool will mean there is less chance
that a plant exists with the genes to resist the environment
change, so all the plants of this species may die
In-breeding tends to lead to individuals that have two recessive
alleles (homozygous recessive), which can result in defects
15
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
The working plant
Plants the producers
1
a Sugars (e.g. glucose), starch
b Carbon dioxide from the air
Water from the soil
c Chlorophyll
d
light
carbon
+
+ water →
energy dioxide
glucose
+ oxygen
(contains stored (waste gas)
chemical energy)
e light energy + 6H2O + 6CO2 → C6H12O6 + 6O2
2
a Starch molecules are large and so cannot diffuse out of the
storage cells (too large to pass through the pores in the cell
membrane)
b Sugar molecules dissolve in water and are small enough to
pass through the cell membranes
Molecules moving into and out of cells
1
a Water molecules
b i
The level in Tube A will have dropped; the level in Tube
B will have risen
ii It lets through small particles, such as water, but not
larger particles, such as sugar
iii Marks awarded for:
Water molecules move by osmosis
They move from the weaker solution (Tube A) to the
stronger solution (Tube B)
They move through the partially permeable
membrane
The partially permeable membrane prevents the
sugar molecules from moving to Tube A, they are too
large to pass through the pores
16
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Transport through the plant
1
a
Organ
Function
A
Leaf
Photosynthesis
B
Stem
i Support leaves
ii Transport materials between
roots and leaves
C
Roots
Absorb mineral salts and water,
provide anchorage
D
Flower
Sexual reproduction
b
A
D
B
C
17
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
2 a X – Xylem; Y – Phloem
b
Tissue
X
Y
Main substance
transported
Water and minerals
Sugars dissolved in
water
From
Roots
Leaves
To
Leaves
Roots and growing
regions
Name of this type
of transport
Transpiration stream
Translocation
Water balance
1 a i, ii
Magnified area 40
Guard cells
No
stomata
Stoma
Waxy
cuticle
Stomata
b
i
It is waterproof, so prevents water escaping
ii The lower surface of the leaf does not get as hot as the upper
surface so if the stomata are only on the lower surface of the
leaf, less water will be lost (by evaporation and diffusion)
iii At night photosynthesis is not occurring, so the stomata do
not need to be open for CO2 to diffuse in. Closing the
stomata reduces water loss by diffusion
When transpiration is very rapid, closing the stomata will
reduce the rate of water loss
18
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Health in the balance
Stable inside
1
a Three examples from:
Temperature
Glucose concentration
pH
Urea concentration
Oxygen
Carbon dioxide concentration
b The amount lost
Keeping the cells respiring
1
carbon
energy
glucose
+ oxygen →
+ water +
dioxide
released
(contains stored
chemical energy)
2
C6H12O6 + 6O2 → 6CO2 + 6H2O
3
a
oxygen, glucose
carbon dioxide
b Diffusion
c The lungs (alveoli)
d The heart
4
a Carry out respiration more quickly
b It will increase
As the cells are respiring more quickly, they will be
producing carbon dioxide more quickly, which will diffuse
into the blood more quickly
c Carbon dioxide is toxic in large amounts
19
Co-ordinated Science 2
Year 11 Collins Student Support Materials
d i
ISBN 0 00 715667 7
The brain (medulla of the brain)
ii The medulla (brain) sends nerve impulses to the
diaphragm and intercostal muscles
These contract and relax more quickly causing the
breathing rate to increase
e More oxygen will diffuse into the blood, therefore the
oxygen level will rise
More carbon dioxide will diffuse out of the blood into the
air, therefore the carbon dioxide level will drop
Stable body temperature
1
The amount you lose
2
Through chemical reactions in the cells, in particular
respiration
3
In the (hypothalamus of the) brain, which monitors the
temperature of the blood flowing through it
4
a It must increase
b One (for Foundation level) or two (for Higher level) from:
Sweat glands – produce sweat, which evaporates at the
skin surface transferring heat from the skin to the
escaping water vapour
Capillaries near the skin’s surface – dilate allowing more
blood to flow through them, which allows more heat to
be transferred from the blood to the skin (from where it
can be transferred to the environment)
20
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
Excretion and water balance
1
a Filter it
b Urea, salts, water
2
Kidney
Renal artery
Ureter
Bladder
Urethra
3
It is toxic
Defence against disease
1
a Marks awarded for:
Each cell or microbe has an antigen (protein pattern) on
its surface
The microbe, in this case a virus, has a different antigen
from the body’s cells and the lymphocyte can recognise
this difference
b Antibodies
21
Co-ordinated Science 2
Year 11 Collins Student Support Materials
ISBN 0 00 715667 7
c Two from:
The antibodies have a shape which matches the virus
antigen
The antibodies bind to the virus antigen
This causes the viruses to clump together and damages
them
Drugs and poisons
1
a A stimulant makes you feel more alert, a depressant makes
you feel less alert
b A stimulant increases the heart and breathing rates, a
depressant decreases them
c A stimulant causes more transmitted chemical to be
produced at the synapses, therefore more nerve impulses
are sent down the next neurone, depressants have the
opposite effect
2
Stimulants: caffeine, nicotine, amphetamines
Depressants: alcohol, glue solvents, cannabis
3
Reduces concentration
Causes blurred vision and drowsiness
As alcohol is a depressant it causes less chemicals to be produced
at the synapses, therefore fewer nerve impulses are sent and the
time taken to react to stimuli increases (Higher level only)
4
22
a Marks awarded for:
The addict will crave the drug, depend on it
If the drug is not taken, the addict will suffer withdrawal
symptoms
For example, hallucinations, shaking
b Addicts become tolerant to a drug when they need to take
more to experience the same effect
Addicts can turn to crime because they need money to buy
more and more of the drug