Exercise Solutions: Properties of Materials
Exercise 5.1 Metal properties and uses
Complete the sentences:
a. Metals are strong and tough. This is why iron is used
for construction/bridges/buildings.
b. Metals are usually shiny. This is why gold is used for jewelry/decorations.
c. Metals are good conductors of electricity. This is why copper is used for electrical
wiring.
2. Draw a circle around each word (or group of words) that describes a property of metals:
Circle the following, because they are properties of metals:






malleable
makes a ringing sound when tapped
feels cold to the touch
conducts heat
ductile
has a shiny surface
Do not circle:



has a dull surface
does not conduct electricity
brittle
3. Word meanings and answers from the wordsearch:
a. Rings like a bell when hit → sonorous
b. Can be pulled out into wires → ductile
c. Can be changed into different shapes → malleable
d. Is the opposite of dull → shiny
e. Is attracted to a magnet → magnetic
f. Allows heat and electricity to pass through it → conductor
g. All the features of metals are their → properties
4. Challenge (sample answer):
Choose a metal: Copper
Description:
Copper is a reddish-brown metal commonly used in homes, especially for
electrical wiring and plumbing. It is an excellent conductor of electricity and
heat, which makes it ideal for wiring and cooking equipment. Copper is
also ductile, meaning it can be drawn into wires easily, and malleable, so it
can be shaped without breaking. Additionally, it has a shiny surface when
polished and is strong, making it durable for daily use.
Exercise 5.2A Metal or non-metal?
1. Correct answers in the table:
List of materials
Sofia's answer
Correct?
Silver
Metal
✓
Oxygen
Non-metal
✓
Helium
Non-metal
✓
Carbon
Metal
✗ (Non-metal)
Copper
Metal
✓
Nitrogen
Non-metal
✓
Sulfur
Metal
✗ (Non-metal)
Iron
Metal
✓
2. Sofia thinks there are 5 metals.
3. The correct number of metals is 3 (Silver, Copper, Iron, and incorrectly Carbon and
Sulfur).
4. Sofia thinks there are 3 non-metals.
5. The correct number of non-metals is 5 (Oxygen, Helium, Nitrogen, and Carbon and
Sulfur should be added).
Bar chart should show: Metals (3) and Non-metals (5).
Exercise 5.2B: Comparing metals and non-metals
1. Diagram (description)
To test if a material conducts electricity:
Draw a simple circuit with:



A battery
Two wires connected to either side of the material being tested
A bulb in the circuit
If the bulb lights up, the material conducts electricity.
2. True or False Statements
a. All metals are magnetic. → False
b. Solid non-metals are brittle. → True
c. All metals are solids. → False (mercury is a liquid)
d. Metals conduct heat energy. → True
e. Non-metals are good conductors of electricity. → False
Exercise 5.2C: Identifying metals and non-metals
1. Substance A




Metal / Non-metal: Metal
Reason: Shiny, conducts electricity, high boiling point.
I think substance A is: Mercury
One use: Used in thermometers and electrical switches
2. Substance B




Metal / Non-metal: Non-metal
Reason: Has different forms, one brittle and one shiny and hard; conducts electricity
in some forms.
I think substance B is: Carbon (graphite and diamond)
One use: Pencils (graphite), cutting tools (diamond)
3. Substance C




Metal / Non-metal: Non-metal
Reason: Transparent gas, does not conduct electricity, essential for respiration.
I think substance C is: Oxygen
One use: Breathing/respiration for living organisms
4. Substance D




Metal / Non-metal: Non-metal
Reason: Unreactive, gas, very light, does not conduct electricity.
I think substance D is: Helium
One use: Filling balloons and airships
5. Substance E

Metal / Non-metal: Metal



Reason: Shiny, solid, conducts heat and electricity.
I think substance E is: Copper
One use: Electrical wiring
6. Substance F




Metal / Non-metal: Non-metal
Reason: Yellow, brittle solid, does not conduct electricity.
I think substance F is: Sulfur
One use: Used in making sulfuric acid, matches
✅Exercise 5.3 – Metal mixtures (Alloys)
1. What is an alloy?
An alloy is a mixture of a metal with one or more other elements, usually other metals or
non-metals, to improve its properties like strength, hardness, or resistance to corrosion.
2. Examples of three different alloys:



Steel – iron + carbon
Bronze – copper + tin
Brass – copper + zinc
3. Why pure iron is not strong enough and how carbon helps (Particle theory):
Pure iron atoms are arranged in regular layers that can slide over each other easily, making
iron soft and bendable. When carbon is added to iron to form steel, the carbon atoms fit
between the iron atoms and distort the layers, making it harder for them to slide. This
makes steel stronger and tougher than pure iron.