Examination
Year 8 Science
Semester 2
Name
Item
Teacher
Time Allowed: 60 minutes
Individual Assessment
Supervised Examination
Everyday language
Chemistry
Examination
Date of
Completion
Specialised language
Field
Informal language
Topic
Assessment
Type
Class
Conditions
5
Neutral language
Highly technical language
X
Formal language
Tenor
X
Most spoken
Written texts spoken aloud
Most written
X
Mode


Steps to
Follow and 
Instructions
Write all answers in the spaces provided on the question sheet.
Calculators are permitted and round off any decimal answers correct to 2
decimal places.
If you feel a question is ambiguous or unclear in its meaning or that there is
insufficient data, state your position and continue. The validity of your
argument will be taken into account when the paper is evaluated.
Summary of Results
Formative
Summative
X
Criteria
Scientific Understanding
Scientific Inquiry Skills
A
A
B
B
C
C
D
D
Page 1
E
E
Years 8 learning area standards descriptors: Science
Scientific
Concepts
Assessed
Understanding





Skills

Properties
of matter
and the
particle
theory
Physical
and
chemical
change
Density
Elements
and the
periodic
table
Compounds
and
mixtures
Chemical
equations
A
B
C
D
E
Statements of scientific
information and
science knowledge.
Statements of isolated
information.
The folio of student work has the following characteristics:
Comprehensive
description and
explanation of scientific
information, concepts
and relationships.
Q10
Use of science
knowledge to generate
solutions and justified
explanations in a range
of situations, including
some that are complex
and unfamiliar.
Significant description
and explanation of
scientific information,
concepts and
relationships.
Q9a
Description and
identification of
scientific information
and concepts.
Q1-5, Q6, Q7
Use of science
knowledge to generate
solutions and informed
explanations in
complex familiar
situations.
Use of science
knowledge to generate
solutions and
explanations in simple
familiar situations.
Use of science
knowledge to generate
partial solutions and
explanations.
Q9b
Q8
The folio of student work has the following characteristics:
Analysis of trends in
data to identify and
explain relationships
between variables to
draw justified
conclusions.
Q15b, Q16b
Analysis of trends in
data to identify and
describe relationships
between variables to
draw conclusions
consistent with
evidence.
Q13b, Q14
Page 2
Analysis of trends in
data to identify
relationships between
variables.
Q11, Q12, Q13a, Q15a,
Q16a
Statements about
trends and
inconsistencies in data
and information.
Statements about data.
Scientific Understanding
Question 1* Identify in which state of matter the forces holding particles together are the strongest.
a) Gas
b) Solid
c) Liquid
d) Plasma
Question 2* Identify which of the following is a pure substance.
a) A substance that has tiny particles suspended in solution.
b) A substance that contains particles that are all the same type.
c) A substance that has particles dissolved throughout the solution.
d) A substance that contains several different types of particles mixed together.
Question 3* A gold miner shakes a mixture of mud and water in a gold pan. Identify the reason why he
looks for the gold at the bottom of the pan.
a) Gold is hard to find because it can ‘hide’.
b) Gold is repelled by other earth’s minerals.
c) Gold is very dense and sinks to the bottom of the pan.
d) Gold dissolves in water and is carried to the bottom of the pan.
Question 4* Identify which scenario indicates that a chemical reaction has occurred.
a) Salt dissolves in water to form a solution.
b) A block of chocolate left in a hot car melts.
c) A concrete path cracks due to intense heat.
d) A glow stick is snapped, shaken slightly and then begins to glow.
Question 5* Read the following statements about elements and compounds and identify which
statement is correct.
a) Elements are unable to exist as molecules.
b) Metallic elements tend to appear dull and are used as insulators.
c) Elements are substances that are made up of several different atoms.
d) Water is a molecular compound (H20) containing the elements hydrogen and oxygen.
Page 3
Question 6* Identify the reactants in the following chemical equation by circling your response:
Nitric oxide + Ozone  Nitrogen dioxide + Oxygen gas
Question 7* Carbon dioxide molecules are naturally found in our atmosphere. In the table below,
identify the name of each type of atom, the number of each type of atom, and the total number of atoms
present in a carbon dioxide molecule.
CO2
Name of Atoms
How many of each type of atom
Total Number of atoms
Question 8**. Amy is making pancakes for breakfast using the following recipe she found online:
PANCAKE RECIPE
1. Mix flour and sugar in a large bowl.
2. In a small jug add sodium bicarbonate to buttermilk and allow to stand until frothy.
3. Crack one egg into the small jug, beat gently.
4. Add wet ingredients into the dry ingredients and mix.
5. Place tablespoons of the mixture into a heated frypan and flip when bubbles appear on the
outside of the pancake.
Identify and explain one chemical change which occurs during the process of making pancakes for
breakfast.
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Page 4
Question 9 An unidentified element is found by two astronauts on the planet Mars.
The astronauts conducted several experiments on the element and the observations they made are
summarised in the table below.
Experiment
Observation
Heated by the flame of a Bunsen burner
Glowed red
Ability to be cut with a knife
Easily done
Reflective ability
Able to reflect light, appears shiny
Based on these observations Astronaut A decides it should be classified in the periodic table as a metal.
However, Astronaut B thinks it should be classified as a non-metal.
a)** Evaluate what supporting evidence each argument has.
b)*** Give a justified explanation of what additional evidence would be required to confirm the
elements classification as a metal or non-metal.
Page 5
Question 10*** A teacher was trying to find out what a group of students knew about heating, cooling, and
the particle model. She put a balloon over the top of a plastic bottle as shown in the diagram (Fig. 1). She
asked the students to write down what would happen, and why, if she put the bottle in a large beaker of hot
water.
The following is what three of the students wrote:

Megan wrote: ‘The balloon will get bigger that is because the air
particles get bigger when they are heated.’

Bill wrote: ‘The balloon will get bigger that is because the air
particles have more energy and move faster, so they will move into
the balloon and hit its wall with strong force.’

Susan wrote: ‘The balloon will get bigger that is because all of the
particles in the bottle will move into the balloon.’
Fig. 1
Identify which student’s response is correct and justify your choice using your knowledge of the particle
theory of matter.
Page 6
Scientific Inquiry
Question 11*. Using the above periodic table identify which element is represented by the symbol Cl.
a) Calcium
b) Chlorine
c) Magnesium
d) Nitrogen
Question 12* Using the above periodic table identify the symbol used to represent sodium.
a) Cl
b) Na
c) S
d) Si
Page 7
Question 13 The diagram below shows the arrangement of particles in four different substances (A, B, C,
and D).
a)* Identify each of these substances as either an element, compound, or mixture and complete the table
below.
Element, Compound, or Mixture?
A
B
C
D
b)** Using your knowledge of elements, molecules and compounds, describe 2 pieces of evidence used to
reach your conclusion for SUBSTANCE B.
Evidence
1
Evidence
2
Page 8
Question 14** The table below shows the melting points and boiling points of four imaginary elements.
Complete the table below, stating whether the substance is a solid, a liquid or a gas in a room that is 20°C.
Element
Melting Point (°C)
Boiling Point (°C)
Xyggium
-189
-186
Zrttord
YYrtesium
Caetriol
714
-39
44
1640
357
280
State at 20°C
Question 15 Table 1 below shows the mass of various liquids, each with a volume of 100mL.
Table 1.
Type of Liquid
Mass of 100mL of Liquid (grams)
Petrol
Fresh Water
Blood
Glycerine
70
100
105
126
The density of any substance can be determined by using the formula:
mass (g)
Density (g/mL) =
volume (mL)
a)* Calculate the density, in g/ mL, for the two liquids listed below.
Blood
Glycerine
Page 9
b)*** Mercury is a liquid with a density of 140 grams per 100 mL. Using the information in Table 1
identify substance/s that would sink in water but would float on mercury. Justify your decision.
Page 10
Question 16 When magnesium is burnt it combines with oxygen in the air to create magnesium oxide.
The graph below shows the amount of reactants and products present during this chemical reaction
experiment over time.
Amount of Substance (mg)
Line X
Line Y
Time
a) * Identify from the graph which line represents the reactants and which line represents the products
from the chemical reaction described above.
Reactants: ___________________________________________
Products: ____________________________________________
b) *** Justify your decision by analysing the trends in the data to explain the relationship over time
between the amount of reactants and products in a chemical reaction.
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Page 11
Year 8 Science – Semester 2 – Item 5 – Marking Scheme
Criterion
Question
Standard A
Standard B
1-5
6
7
Scientific
Understanding
8
9a
9b
10
OVERALL
11
12
13a
13b
14
Science Inquiry
15a
15b
16a
16b
OVERALL
12
Standard C
Standard D
Standard E