Download model answers year 9 practice examination

YEAR 10 PRACTICE EXAMINATION 2008
MODEL ANSWERS
Question Answer
Section
ONE
Q1.a.
b.
c.
d.
e.
f.
g.
h.
i. a
i. b
j.
k.
l.
Acids and Bases
HCl, NaCl, NaOH, H2SO4
i. sour
ii. red
iii. hydrogen
iv. blue
vinegar (ethanoic acid) – acid – used for flavour (sour), used for
preserving (low pH)
baking soda (NaHCO3) – base – decomposes on heating to
produce CO2 used for making baking rise
pH is a scale used to tell us how many hydrogen ions are
present in a solution (ie: how acidic or how basic a substance is)
1 – red
3 – orange
5 – yellow
7 – green
9 – blue
11 – indigo
13 - violet
acetic acid 3 - 4
lemon juice 2 - 3
water 7
salt 7
baking soda 8
sodium hydroxide 13 - 14
Observations:
Bubbles of colourless gas (effervescence)
Zinc metal disappears
Test tube gets warmer
zinc + hydrochloric acid → zinc chloride + hydrogen
Limewater can be used (will go cloudy if CO2 is present)
Two test tubes – one with reacts in it and a second with lime
water - connected with a delivery tube. Bubbles of CO2 will go
into limewater
Indicator
An acidic substance (anything with a pH of less than 7 eg: HCl)
could be added to the solution to get it to turn red / purple
A alkaline substance (anything with a pH of more than 7 eg:
NaOH) could be added to the solution to get it to turn green /
yellow
Method:
Get 3 test tubes.
Add 1 mL of each solution to each test tube.
Add a 2 drops of universal indicator to each test tube solution
Results:
Table salt will turn Universal Indicator green (neutral)
Citric acid will turn Universal Indicator orange – a weak acid –
pH of 2 – 3
HCl will turn Universal Indicator red – a strong acid – pH of 1
Question ATOMIC STRUCTURE
TWo
a.
Proton, relative mass of 1, found in the nucleus
Neutron, no charge
Electron, relative mass is negligible, relative
charge -1, found orbiting outside of the nucleus
b. i
Y and Z are the same atoms
b. ii
The number of protons defines an element
(atom). Both Y and Z have 6 protons
c.
Fluorine, F, 2,7
Sodium, Na, atomic number 11, 12 neutrons, 11
electrons,
Calcium, mass number 40, 20 protons, 20
electrons, 2,8,8,2
d.
NaCl
sodium and chlorine, 1 Na and 1 Cl, total of 2
atoms
NH4NO3
nitrogen and hydrogen and oxygen, 2 N, 4 H, 3
O, total of 9 atoms
Fe(OH)2
iron and oxygen and hydrogen, 1 Fe, 2 O, 2 H,
total of 5 atoms
e.
Magnesium oxide,
Copper sulfate,
Calcium hydroxide
Potassium chloride
Calcium carbonate
Section
TWO
1.a.
b.
c.
d.
FOOD AND DIGESTION
Glucose – add Benedict’s solution - turns solution brick red /
orange
Starch – add iodine – turns blue/black
Protein – Biurets – turns solution purple
Vitamins and minerals – fruits and vegetables – brain
development and learning, enzyme formation
Carbohydrates – potatoes, rice, cereals, fruit – energy
Proteins – meat, fish, chicken, nuts, eggs – growth and repair of
body cells
Fats and oils – nuts, butter, milk – energy / storage- e
Lentils, eggs, milk, nuts, pulses
Food, broken, smaller,
bloodstream,
e.
Question
2
a.
b.
c.
d. i
d. iii
d. iii
d. iv
mouth, teeth / chewing,
saliva
oesophagus, stomach
hydrochloric acid, enzymes
bile
bloodstream , large
intestine / colon, water
rectum, sphincter, anus
Clockwise from left to right
Anus
Large intestine
Liver
Mouth
Oesophagus
Stomach
Pancreas
Small intestine
Rectum
GENETICS
Two
foot length / height
range, second, discontinuous
widow’s peak, eye-colour
 Chromosome number in daughter cells same as in parent
cell, produces 2 new cells with exact copies of the original
chromosomes, for the growth, repair and replacement of
body cells
 Fertilisation, zygote cell formed – a new cell with full
number of chromosomes
 Halves chromosome number - produces 4 new cells (sex
cells – gametes), have half the number of chromosomes
in each cell
Chromosomes – long pieces of DNA wound up. Contains
instructions called genes
Homozygous – 2 of the same copies of an allele: 2 blue eyed
allele)
Allele – different form of a gene
Gene – long piece of DNA that codes for a characteristic
Mutation – change in the DNA sequence of a gene
Brian bb blue eyes,
Laki bb blue eyes
Erana Bb or bb brown or blue eyes
Moana – Bb
Laki – bb
Brian – bb
Bb Bb
bb bb
50 %
d. v
d. vi
Section
THREE
Q 1a. i
a. ii
a. iii
a. iv
a. v
a. vi
a. vii
a. viii
Question
TWO
I
ii. a
ii. b
Iii
Each child is produced from an individual event and they are not
related (eg: tossing a coin). Punnett squares tell you what the
possible chances each time a child is conceived not what the
actual outcome will be.
Phenotype is the physical outcome. In the case of eyes it is the
colour of the eyes. If a parent is homozygous (ie: the genes are
the same BB) then when they have children they must pass on a
brown eyed gene. This gene will always be expressed as it is a
dominant gene to blue eyes. All children produced from a
homozygous brown eyed parent will have brown eyes as they
will either be homozygous for brown eyes BB or heterozygous
for brown eyes Bb.
MOTION
0 – 8 mins – accelerating
8 – 16 mins – constant speed
30 minutes
At 10 minutes
Yacht A - 1200 metres
Yacht B - 1000 metres
Distance between yachts is 200 metres
Correctly completing graph
Yacht A
60 minutes
Yacht A – it accelerated faster away from the start mark – as
can be seen from the steeper gradient of the line
Speed = distance / time
Speed = (1000 – 400) / (30 - 15)
Speed = 600 / 15
40 metres minute-1
FORCES
In a clockwise direction from the left
Forward thrust (drive force), support, friction (drag), gravity
(weight force)
Continues to move at constant speed
acceleration
In space mass = 58 kg
On the Moon mass = 58 kg
On Earth weight = 580 N
iv.
v.
Question
Three
a.
b.
c.
d.
e.
f.
g.
Work = force x distance
Work = 25 x 400
Work = 10000 Joules
Kinetic energy → heat energy
ELECTRICITY
All correct
symbol
Name
symbol
name
Lamp
Battery
Single cell
Voltmeter
Variable
resistor
Fuse
Correctly drawn following the rules
All lines are drawn straight (using a ruler)
Use of correct symbols
All angles are 90o
No components are drawn in the corners of the circuit
No gaps in the circuit
Series
Each bulb gets the same amount of energy (ie: none are brighter
than any other)
If one bulb fails then all the rest will continue to work
Pure water is an insulator, but tap water from contains ions such
as Fluoride and Calcium etc. Ions are charged particles and are
free to move in solution. As a result the charge can complete
the circuit and the person will be electrocuted.
Circuit correctly drawn following rules in b. above
The circuit will include the following components:
Power supply, resistance wire, ammeter
Correctly drawn graph
Voltage against Current
Voltage (V)
15
10
5
0
0
0.2
0.4
0.6
Current (A)
h.
Section
Current at 8 V is 0.6 Amps
Voltage at 2.0 A is 1.2 Volts
EARTH SCIENCE
0.8
1
1.2
FOUR
Q1a. i
a. ii
a. iii
a. iv
b.i
b. ii
b. iii
b. iv
c.
d.
e.
f.
Q 2.a
b.
c.
d.
Inner core
Outer core
Mantle
Crust
Inner core – solid interior due to intense heat and pressure,
made of Nickel and Iron –
Outer core – liquid material
Mantle – liquid material which flows with convection current
Crust - solid outside rock. Varies in depth in continental and
crustal areas
Heat → rising convection current → semi molten rock spreads
out carrying plates with it → cools and sinks down
Subduction – where one plate subducts (moves) underneath
another plate
Subduction occurs in the central North Island where the Pacific
Plate is subducting underneath the Indo Australian Plate
This process that causes volcanism in the central North Island
area. Eg: Mt Ruapehu and Mt Tongararo
Volcanic labels – from bottom left to right
Parasitic cone
Lava bomb
Ash cloud
Pyroclastics flow
Crater
Lava flow
Magma chamber
Mt Eden, Mt Albert, Mt Roskill, Three Kings, Mt St John, Mt
Hobson, Rangitoto, Pupuke,etc
Wellington and Wairarapa – two plates moving past each other
(transform plate boundary)
Erosion and Sedimentation , Heat and Pressure, Melting