C H E M ISTRY
Understanding Elements
Ideas you have met before
❯❯
Materials
All substances are made of different materials. Materials
have different properties; some are harder than others,
some are shinier and some are heavier.
Glass, for example, is a very different material from plastic
or metal.
Metals
Metals are shiny solids that we use for many different
things, such as making cars, computers, bridges and so on.
Metals are good electrical conductors, which is why we
use them to make wires and circuits.
States of matter: solids, liquids and gases
Most materials can be classified into three groups: solids,
liquids and gases.
Ice, water and steam are three states of matter of the
same substance. We can convert materials from solids,
liquids and gases by heating or cooling them.
Physical and chemical changes
Melting ice is reversible. We can put it into a freezer and
produce ice again. This is a physical change.
Some changes are not reversible. These are are called
chemical changes. Making toast is a chemical change; you
can’t change it back into bread.
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In this chapter you will find out
❯❯❯
Elements and atoms
•
Since ancient times materials have been described in
terms of the chemical elements that they contain.
•
Ideas about elements have changed over time.
•
Each element is unique, with its own properties.
The Periodic Table
•
The chemist’s dictionary is called the Periodic Table.
•
The ingredients of the entire universe are listed in
one place.
Using simple models
•
Chemists can represent the building blocks of all
materials using simple circle models and symbols.
•
Chemical models and symbols help us understand
how elements join and react together to make new
materials.
Reactions
•
Chemical elements can join together in many ways to
produce an amazing range of different substances.
•
We can make new materials by chemical reactions
and then use them to do many different things.
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Chemistry
We are learning how to:
Introducing the
Periodic Table of
elements
• Navigate the Periodic Table and
identify some of the elements.
• Identify features of the Periodic
Table and describe how it is
organised.
• Explain why the Periodic Table is
useful.
The Periodic Table lists all the known chemical
elements in our universe. The patterns and trends
in the arrangement help chemists explain and
predict the behaviour, properties and reactions of
all the elements.
Periods and groups
❯
FIGURE 1.3.4a: The Periodic Table of elements
The Periodic Table is arranged in rows called periods and
columns called groups. Groups are families of elements with
similar properties. Group 1 is the alkali metals, which all
react quickly with water. The halogens are in Group 17; they
are good at killing bacteria. The noble gases in Group 18 are
all unreactive gases. These characteristics are called chemical
trends and patterns.
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Another pattern to recognise is that metals are on the
left and non-metals, except hydrogen, are on the right. In
between are metalloids, which have some of the properties
of metals but not all.
1. How many groups make up the Periodic Table?
2. Name three families of elements.
3. The Periodic Table is split into three types of elements:
what are they called?
Atomic number
❯❯
Each element has unique number, called the Atomic number.
This number increases left to right across each period. For
example, hydrogen (H) is number one, lithium (Li) is number
three, carbon (C) is number six and neon (Ne) is number 10.
This is an important pattern in the Periodic Table.
3 .4
Xenon
name of element
element state
Xe
131.29
chemical symbol
54
mass number
atomic number
FIGURE 1.3.4b: Each element has a symbol,
atomic number and mass number.
TABLE 1.3.4: Trends and patterns in
melting and boiling points tell us
about the physical state of elements at
different temperatures
Melting
point
Boiling
point)
1
−210 °C
−196 °C
2
−7 °C
59 °C
5. Use the Periodic Table to answer these questions:
3
328 °C
1750 °C
a) In which group would you find carbon (C)?
4
1064 °C
2856 °C
b) In which period would you find magnesium (Mg)?
5
115 °C
445 °C
4. Describe how the elements are arranged within the
Periodic Table.
Melting and boiling
❯❯❯
Most elements are solids at room temperature, which means
that their melting point is higher than 20 °C. Only two are
liquids at room temperature: mercury (Hg) and bromine (Br).
The melting and freezing point of mercury is −39 °C. It
would still be liquid if you put it in your freezer.
Oxygen (O) is a gas at room temperature, which means that
it has a boiling point below 20 °C. To turn oxygen into a
liquid you would have to cool it to below −183 °C.
6. Look at the elements in the table showing the melting
and boiling points of five different elements.
a) Which one has the lowest boiling point?
b) Which one has the highest melting point?
c) Which one is liquid at room temperature?
Did you know . . . ?
Mercury is sometimes
called quicksilver
and is the only metal
that is liquid at room
temperature. It was
named after the Roman
messenger of the gods;
its symbol Hg is derived
from the Greek word
hydrargyros which
means silver water.
Key vocabulary
7. If the temperature dropped to below room temperature
which element would freeze first? Explain your choice.
the Periodic Table
8. What is the number of the element with a boiling point
lower than oxygen?
group
period
atomic number
the Periodic Table
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Chemistry
Applying key ideas
You have now met a number of important ideas in this topic. This activity is an opportunity
for you to apply them, just as scientists do. Read the text first, then have a go at the tasks.
The first few are fairly easy, then they get a bit more challenging.
How tinny is a tablet?
If we call something ‘tinny’, we’re probably not being very kind about it. If you said that
someone’s car was a bit tinny, they might not be very pleased, as it implies it isn’t very
well made. Tin, however, is very important to us, and has been for thousands of years. It
is a silvery metal which is both malleable and ductile.
Copper has been used for thousands of years to make tools, coins, weapons and
decorations. It isn’t very hard, but it can be alloyed with tin to make bronze, which is
much harder. Roman officers had swords made of bronze, and for many decades bronze
was used to make ships’ propellers, until it was replaced by stainless steel.
For thousands of years one of the main sources of tin was Cornwall. At its height, in
the 19th century, the Cornish tin mining industry produced 10 000 tonnes of tin a year,
from cassiterite, or tin ore, SnO2. The ore is crushed, washed, roasted to remove sulfur
and arsenic as oxides, and then heated
strongly with coal to produce pure tin.
Tin doesn’t easily react with oxygen and
is used to coat other metals such as steel.
A tin can isn’t made of tin but of steel
coated with tin. Tin has a low melting
point compared with other metals and
is used to make solder, which is used to
join electrical components together so
that they make effective and permanent
connections. When heated, the solder
melts and flows onto the contacts; it
then sets hard, fixing the component
into the circuit.
FIGURE 1.3.11a: Soldering
Every tablet contains thousands of
soldered joints and, therefore, several
grams of tin. In fact, it’s one of the
most common metals used in their
manufacture.
FIGURE 1.3.11b
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3 .11
Task 1: Exploring properties
What does tin look like? Explain in simple terms what is meant by tin
being silvery, malleable and ductile.
Task 2: Thinking about alloys
What is meant by an alloy? What has to happen to metals to turn them
into an alloy? How did tin make copper more useful? Copper and tin
aren’t often mined in the same area. Why did bronze depend upon
trade?
Task 3: Applications at sea
What sometimes happens to metals in sea water? What do you think it
was about bronze that made it suitable for making ships’ propellers?
Task 4: Applications in electronic devices
What is it about tin that makes it suitable for use as solder?
Task 5: Finding its family
Find tin on the Periodic Table. What are its neighbours in that group?
Research their properties and find out what they have in common
with tin.
Task 6: Thinking about its ore
What is an ore? The formula of tin ore is SnO2. What does this formula
tell you? Tin ore is roasted to drive off sulfur and arsenic as oxides. What
would the names of the compounds formed be? Why would this be a
dangerous process?
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Chemistry
We are learning how to:
Observing how
elements react in
different ways
• Draw conclusions to explain
observations.
• Use symbols and models to
describe a chemical reaction.
How an element reacts and the products it makes
are unique to the element and the conditions.
These differences can help chemists identify
elements not only on Earth, but out in space, too.
Using flames to recognise metals
❯
Fireworks contain metals and non-metal compounds. It is
the metals that are responsible for the colour; when they
burn at high temperatures, they give off distinct colours.
FIGURE 1.3.15a: Fireworks use different
metal compounds to produce different
colours.
TABLE 1.3.15
Metal
Flame colour
potassium
lilac
calcium
yellow
iron
orange
copper
green/blue
magnesium
white
strontium
red
barium
green
Carbon and sulfur combined act as a fuel that launches the
firework and keeps it burning. When non-metals like these
burn, they produce gases. Both sulfur dioxide and carbon
dioxide dissolve in water to form acids. When metals burn
the products are solid oxides that are the opposite of acids;
these are called bases.
1. If an unknown compound turned a Bunsen flame green,
what conclusion could you draw?
2. Which reactants will form the product sulfur dioxide?
3. What are the reactants if sodium oxide is produced?
FIGURE 1.3.15b: Sodium burns with
a yellow flame and produces a white
powder called sodium oxide, Na2O.
O
S
O
Na
O
Na
FIGURE 1.3.15c: Different oxide
compounds.
4. How could you tell that it is sodium not sulfur burning?
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Temperature matters
❯❯
3 .15
The temperature that substances are heated to is important.
There has to be enough energy and air for elements to
burn. The reaction not only forms an oxide, it also emits
light. The colour of the light depends on the element, but
the colour of the sparks produced by burning iron depends
on the temperature. The colour changes from orange at
lower temperatures to white when it is very hot.
Key changes indicate that a chemical reaction has happened:
•
Has the substance permanently changed its
appearance?
•
Are there gas bubbles or a new smell?
•
Has the temperature gone up or down? Can you feel
heat?
•
Change of pH – has an acid or base been produced?
5. List the substances found in fireworks and the reasons
they are included.
Did you know . . . ?
Astronomers use
special machines called
spectrometers to study
light that is emitted from
distant stars and galaxies.
Stars inside a nebula glow
with beautiful reds, blues,
and greens due to the
different elements within
the vast clouds of gas.
6. List the evidence for burning sulfur being a chemical
reaction.
7. Explain the difference between melting iron and
burning iron in as much detail as you can.
8. Write a word equation for the burning of iron.
White light and smoke
❯❯❯
Zinc is used in fireworks to create smoke effects as zinc
oxide (ZnO) is a non-toxic, fine white power. Zinc oxide is
insoluble and is often used in sunscreens. Magnesium is used
in fireworks and sparklers as it produces bright white sparks
and ultraviolet (UV) light. UV light is emitted by the Sun and
can damage your eyes. It is the reason you wear sunglasses
and protect your skin with sunscreen.
9. What are the advantages and disadvantages of using
magnesium in fireworks?
10. Use word equations and circle diagrams to represent
the burning of zinc and magnesium in fireworks.
FIGURE 1.3.15d: Gas cloud nebula,
galaxy and stars
Key vocabulary
fuel
burning
acid
product
base
reacting elements and oxygen
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Chemistry
We are learning how to:
Choosing elements
for a purpose
• Recognise elements and their
differences from physical data.
• Use data and the properties
of elements to choose suitable
materials.
It is important that scientists can make good
observations and interpret information. They use
their knowledge to explain what the patterns in
data mean. Companies use scientists to find out
the best materials to use in new products.
Gallium
❯
Gallium is a non-toxic, shiny metallic element in Group 3,
underneath aluminium. It melts in your hand because it has
a low Melting point of 29.8 °C. It also shatters like glass if
you hit it and it will attack metals like aluminium by forming
alloys with them.
1. Why would gallium be a poor choice for a drink can?
FIGURE 1.3.10a: Gallium is a metal that
melts in your hand
2. Which properties are important in a drink can?
Problems with metals
❯❯
Some elements are toxic (poisonous) to humans, making us
ill and even causing death over a certain amount. Metals like
lead and mercury are stored in our bodies over time and are
linked to problems with the brain and nervous system. They
were used in the past in paints, dental fillings, water pipes
and make-up, until we realised how harmful they were.
The reactions of different metals with air and water vary.
Some, like gold, don’t react with either. Group 1 elements
like potassium react quickly with oxygen in air and violently
with water. Aluminium reacts quickly with oxygen in air but
the reaction forms a protective oxide layer over the metal
which stops it reacting with anything else. Iron reacts slowly
with air and water, forming rust, which weakens the metal.
3. Give two reasons why neither lead nor mercury would
be good materials for a drink can.
4. Compare the use of gold and iron as materials for a
drink can.
Selecting the right metal
❯❯❯
FIGURE 1.3.10b: Drink cans are made
of metal
Density helps us understand how heavy substances are,
compared to their volume. The greater the density, the heavier
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the substance would be. If blocks of lead and aluminium
of the same size were placed on the balance, the lead one
would be heavier, because it has a greater density.
Sometimes the best material for the job is not chosen as it is
too expensive. Silver is a better conductor of electricity than
copper, but is only used in specialist items such as satellites.
Table 1.3.10 gives data about the properties of 10 elements,
which tell us a lot about their appearance and behaviour.
3 .10
aluminium
(2.7 g/cm3)
lead
(11.3 g/cm3)
FIGURE 1.3.10c: If different metals are
each made into blocks of the same size,
the denser one would be heavier.
TABLE 1.3.10
Density
(g/cm3)
Cost pure
($/g)
Other
properties
element
Conducts
heat
Conducts
electricity
Melting
point (°C)
graphite
not well
yes
3730
2.25
2.4
brittle
helium
no
no
−270
0.15
5.2
inert
lead
yes
yes
327
11.30
2.5
poisonous
aluminium
yes
yes
660
2.70
15.7
protective
layer
hydrogen
no
no
−259
0.07
12.0
flammable
silver
yes
very well
961
10.50
120.0
gallium
yes
yes
29.8
5.91
5.0
sodium
yes
yes
97.8
0.97
25.0
iron
yes
yes
1535
7.86
7.2
rusts
copper
yes
very well
1083
8.92
9.8
non-toxic
5. Which of the elements in the table are not solids at
room temperature (20 °C)?
6. a) Give one reason for and one against for using
graphite to make a drink can.
b) Choose the material you think would be most
suitable for a drink can and explain why.
c) Rank the elements in order from most suitable to
least suitable.
7. Joe has suggested using copper to make his drink can
because it conducts heat and electricity well and he
likes the orange colour. Explain to Joe why his choice is
good, but that there are better alternatives.
shiny
poisonous
very
reactive
Did you know . . . ?
Gold jewellery and silver
coins are ‘fake’! Nine carat
gold is less than half gold
as pure gold is too soft.
50p coins are 75 per cent
copper and 25 per cent
nickel, which is cheaper
and harder than silver.
Key vocabulary
melting point
toxic
density
properties of elements on the Periodic Table
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Understanding Elements
3.2 Recognising materials, substances and elements
Lesson overview
Learning objectives
 Recognise the difference between materials, substances and elements.
 Identify elements by their names and symbols.
 Explain what is meant by a chemically pure substance.
Learning outcomes
 Classify substances as materials, pure substances, compounds or elements. [O1]
 Interpret the names and symbols of common elements and compounds. [O2]
 Explain the difference between pure and chemically pure substances. [O3]
Skills development
 Thinking scientifically: Use units and nomenclature.
 Working scientifically: Develop explanations.
 Learner development: Ask questions.
Resources needed Range of substances, names, objects, labels
Common misconceptions Materials are all fabrics/clothing; water/orange juice are chemically pure or single
substances.
Key vocabulary pure, element, compound, symbol, material
Teaching and learning
Engage
 Identify students’ prior knowledge by giving them a series of different materials or pictures, e.g. bottle of
water/pure orange juice carton, metal, plastic, glass, charcoal or graphite, wood, NaCl salt, fabric. Ask them to
identify what the items are made of and then classify them into groups. [O1]
 Explore the idea of materials being made of different substances by means of a group discussion. [O1]
More able students may make links to materials being made of particles by referencing prior knowledge of solids, liquids
and gases.
Challenge and develop
 Ask students to identify the substances that are pure using questions such as, 'How do you know that
substances are pure?' [O3]
 Use the labels of water and orange juice packaging to make observations about the number of substances
and conduct simple experiments, e.g. evaporate water to show residue of salts. [O1,2&3]
 Ask students to list observations about names and symbols of materials e.g. iron nail (Fe), graphite (C),
salt/sodium chloride (NaCl) using questions such as, 'Are they single pure substances?' [O2]
 Discuss how the names and symbols give clues to their composition. Introduce the idea of elements being
the simplest pure substances. [O1&2]
Explain
 Show the Periodic Table and explain that it includes all the chemical elements (symbols as well as names);
everything in the universe is made up of a combination of these elements, e.g. NaCl, called compounds. [O2]
 Orientate students with the Periodic Table by choosing element symbols for them to find and name, e.g. Al,
N, He, Pb. Ask, 'Which elements have you heard of?', 'What are their symbols?' [O2]
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Understanding Elements
More able students may be able to predict symbols from names of elements and identify elements that have symbols not
linked to their English names, e.g. Lead (Pb); gold (Au).
 Pair talk: Students should study the Periodic Table and identify similarities/differences, e.g. what do they
notice about the symbols? Identify rules: always capital letter at start, 1 or 2 letters, none the same. [O2]
 Ask students to explain why every element has a different symbol by asking, 'How would you recognise
whether a substance was an element or a compound?' [O1]
Consolidate and apply
 Ask students to classify substances, compounds and elements using symbols and record their
observations on Worksheet 3.2. This will help to orientate and familiarise students with common names and
symbols. [O1]
More able students should be challenged to explain, with correct terms and examples, the differences between a)
substance, element and compound; b) chemically pure and naturally pure substances.
 Pair talk/Pairs to fours: Students should test each other on symbols or take turns to list as many element
names as they can in 30 seconds. [O2]
 Ask students to identify which elements they think may be present in the body. They should check their ideas
against the table in the student book and collaborate to develop answers to the questions. [O1]
Extend
For students making greater than expected progress:
 Ask questions about the relative size of elements: 'Which are bigger – elements/compounds or cells?'; 'What
are cells made of?' [O1]
 Consolidate understanding by making it clear that cells are made of chemical substances and structures.
Explain that these cells are made of combinations of the 92 elements, therefore elements and compounds are
much smaller than cells. (Particles as atoms are introduced later.) [O1]
Plenary suggestions
“I think that is…because…” Name various substances and ask students to identify them as materials, pure
substances, compounds or elements. [O1,2&3]
Answers to Student Book
1
2
3
4
5
6
7
8
9
C
Two capital letters means two elements – in this case, hydrogen and oxygen. The number signifies two of hydrogen to
every one of oxygen.
Carbon, hydrogen and oxygen
CO is a compound of carbon and oxygen; Co is an element (cobalt).
Chemically pure water contains only one substance/is a compound (H2O) but bottled water is a mixture of many
substances.
It is a compound/single chemical substance made of three different elements joined together/has three capital letters,
and therefore is not a single element.
'Pure' makes things sound natural, safe, clean and good for us.
Blood is a mixture of water, salts and haemoglobin. Haemaglobin is a compound/contains only one type of substance.
Graph (pie chart or bar chart) appropriately scaled (0.05%–65%) and containing symbols.
Answers to Worksheet 3.2
1
2
3
Evaporation
a) compound b) mixture c) element d) mixture e) element
It could be ground up, have water added to dissolve the soluble components, filtered and then have the water
evaporated.
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Getting the energy to move
1.2 Exploring a Healthy Diet
 The importance of the food groups
1 Summarise the importance of each of the food groups
Food group
Importance in the human body
Carbohydrate
Protein
Fats
Vitamins
Minerals
Fibre
Water
 Which food groups?
2 For each of the people below, decide which food group(s) would be most important for
them.
a A builder needing lots of energy to work
b A person suffering from constipation
c A male model wanting to build up his muscles
 Diet or supplements?
You have a friend who has a very poor diet, eating lots of crisps and chocolate and hardly any
fruit or vegetables. They tell you that they have vitamin supplements and so don’t need to
worry about what they eat.
3 Write a letter to your friend explaining why they should also think about eating a healthier
diet.
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Understanding Elements
3.6 Finding the density of an irregularly shaped object
In this practical you will find the density of an irregularly shaped object.
Apparatus
balance
measuring cylinder wide and deep enough to hold object
irregularly shaped object
SAFETY INFORMATION
Water is a suitable liquid for this investigation.
Method
1 Find the mass, m, of the object using a balance as shown.
Record its mass.
2 Choose a measuring cylinder that is wide and
deep enough to hold the object.
3 Add liquid to fill the cylinder to a deep enough
level so that the object will be completely
submerged.
4 Measure the volume of liquid, V1. Record it.
5 Lower the object into the liquid (without
splashing).
6 Measure the new volume V2. Record it.
Analyse and interpret data
7 Calculate the volume of the object V2 – V1. Record it. Calculate the volume of the object V2 – V1.
Record it.
8 Calculate the density of the object from the mass and the volume. Record it.
9 Why will a narrower cylinder give a more accurate answer than a wider one?
10 Why is the volume of the object V2 – V1?
Evaluate data and methods
11 How could you check your value for the density?
12 Why is it important that you do not splash when lowering the object into the liquid?
a)
How could you check your value for the density?
b)
Why is it important that you do not splash when lowering the object into the liquid?
d)
How could you check your value for the density?
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Electricity and magnetism
6.3 Materials, substances and elements
Technician’s notes
Be sure to check the latest safety notes on these resources before proceeding
The following resources are needed for the class demonstrations, P2b.1:
Introduction
pictures of typical electrical hazards – frayed cables, over-long cables, damaged plugs, damaged sockets, water
near sockets, incorrect objects inserted into sockets, metal object put into objects such as toasters, overloaded
sockets (through use of multiplugs).
access to the laboratory's RCCB
Earth safety
12 V AC supply with earthing point
ray box lamp with metal outer casing
coil of 5 A fuse wire
two red 4 mm leads, black 4 mm lead, green or yellow 4 mm lead, brown 4 mm lead, blue 4 mm lead
heatproof mat
two crocodile clips
The power pack needs to supply at least 6 A to ensure that the fuse blows.
Check that the voltage used is sufficient to blow the fuse before the activity.
The following resources are needed for the class practical P2b.1a, per group
20 mm glass bodied fuse rated at 800 mA
12 V ray box lamp or similar
ammeter (0–1 A)
four 4 mm leads
two crocodile clips
variable DC power supply for ray box
The lamp needs to be rated at 12 W or 24 W, so that the fuse blows before the lamp does. Subdued
lighting makes it easier for the students to observe the glow of the fuse just before it melts.
Take care as the fuse is very hot.
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Key Stage 3 Science Overview of Structure
BOOK 1
B1 Cells
Cells and organisation
 Cells as the fundamental unit of living
organisms, use of light microscope
 The functions of the cell wall, cell
membrane, cytoplasm, nucleus,
vacuole, mitochondria and
chloroplasts
 The similarities and differences
between animal and plant cells
 The role of diffusion
 The structural adaptations of some
unicellular organisms
 Hierarchical organisation of
multicellular organisms
Reproduction
 Reproduction in humans (as an
example of a mammal)
 Reproduction in plants
C1 Understanding elements
The Periodic Table
 The principles underpinning the
Mendeleev Periodic Table
 The chemical properties of metals
and non-metals
 Chemical symbols and formulae
Atoms, elements and compounds
 Differences between atoms, elements
and compounds
 The difference between chemical and
physical changes
 Concept of a chemical reaction;
combustion as an example
P1 Forces and their effects
Forces
 Forces as pushes or pulls, the
interaction between two objects
 Moment as the turning effect of a
force
 Using force arrows in diagrams,
balanced and unbalanced forces
 Forces associated with deforming
objects
Forces and motion
 Forces being needed to cause
objects to move (qualitative only)
 Speed = distance ÷ time
 Hooke's Law as a special case
 Work done and energy changes on
deformation
B2 Eating, drinking, breathing
The breathing (gas exchange) system
 The structure and functions of the
gas exchange system in humans,
including adaptations to function
 The mechanism of breathing, using a
pressure model
 The impact of exercise, asthma and
smoking
Human nutrition and digestion
 Content in a healthy human diet
 Calculations of energy requirements
in a healthy daily diet
 The consequences of imbalances in
the diet
 The tissues and organs of the
digestive system
 The importance of bacteria in the
digestive system
C2 Mixing, separating and reacting
Pure and impure substances
 Mixtures including dissolving
 Techniques for separating mixtures
 The identification of pure substances
 Conservation of mass changes of
state and chemical reactions.
Chemical reactions
 Combustion, thermal decomposition
and oxidation reactions
P2 Energy transfers and sound
Changes and transfers
 Examples of processes that cause
change, work = force x distance
 Fuel, fuel sources and heating
Energy and waves
 Sound waves carrying energy
Sound waves
 Frequencies; echoes, reflection and
absorption of sound
 The speed of sound in air
 Sound produced by vibrations of
objects
 Auditory range of humans and
animals
©HarperCollinsPublishers 2013
Key Stage 3 Science Overview of Structure
BOOK 2
B1 Getting the energy to move
Cellular respiration
 Aerobic and anaerobic respiration in
living organisms
 The word equation for aerobic
respiration
 The word equation for anaerobic
respiration
 The differences between aerobic and
anaerobic respiration
The skeletal and muscular systems
 The structure and functions of the
human skeleton
 Biomechanics
 The function and antagonistic actions
of major muscle groups
C1 Explaining physical changes
The particulate nature of matter
 The properties of states of matter
Particle model
 Particles explaining changes of state,
shape, density and diffusion
 A simple (Dalton) atomic model
Physical changes
 The difference between chemical and
physical changes
 Conservation of material and of
mass, and reversibility
 Brownian motion in gases
 Diffusion in liquids and gases driven
by differences in concentration
Energy in matter
 Changes with temperature in motion
and spacing of particles
 Energy changes on changes of state
P1 Pressure and non-contact forces
Static electricity
 Non-contact forces
 Separation of positive or negative
charges
 The idea of electric field
 Gravity forces acting at a distance on
Earth and in space
Pressure forces
 Atmospheric pressure
 Pressure in liquids
 Pressure measured by ratio of force
over area – acting in all directions
B2 Interdependence and plants
Photosynthesis
 The reactants in, and products of,
photosynthesis
 The dependence of almost all life on
Earth on photosynthesis
 The adaptations of leaves for
photosynthesis
Relationships in an ecosystem
 The interdependence of organisms
 The importance of plant reproduction
through insect pollination in human
food security
 How organisms affect, and are
affected by, their environment
 The role of variation
C2 Explaining chemical changes
Chemical reactions
 Combustion
 Chemical reactions as the
rearrangement of atoms
 Representing chemical reactions
using formulae and using equations
 What catalysts do
Acids, alkalis and neutralisation
 Defining acids, bases and alkalis in
terms of neutralisation reactions
 Indicators and the pH scale for
measuring acidity/alkalinity
 Reactions of acids with metals to
produce a salt plus hydrogen
 Reactions of acids with alkalis to
produce a salt plus water
P2 Electricity and magnetism
Current electricity
 Electric current, circuits
 Potential difference
 Differences in resistance
 Calculations of current, power and
energy transfer for series circuits
Magnetism
 Magnetic poles, attraction and
repulsion; magnetic fields
 Earth’s magnetism, compass and
navigation
 The magnetic effect of a current,
electromagnets, D.C. motors
©HarperCollinsPublishers 2013
Key Stage 3 Science Overview of Structure
BOOK 3
B1 Genetics
Inheritance, chromosomes, DNA and
genes
 Heredity as a process
 A simple model of chromosomes,
genes and DNA in heredity
 Variation between species and
between individuals
 Variation and extinction
 The importance of biodiversity
 The use of gene banks
C1 Extracting useful materials
Chemical reactions
 Displacement reactions
Materials
 The order of metals and carbon in the
reactivity series
 The use of carbon in obtaining metals
from metal oxides
 Ceramics, polymers and composites
P1 Balanced forces and motion
Describing motion
 The representation of a journey on a
distance-time graph
 Relative motion: trains and cars
passing one another
Balanced forces
 Opposing forces and equilibrium
Space Physics
 Gravity force, weight = mass x
gravitational field strength (g)
 Our sun as a star, other stars in our
galaxy, other galaxies
 The seasons and the Earth’s tilt
 The light year as a unit of
astronomical distance
B.2 Health and drugs
Microbes and disease
 Embed and develop ideas from
earlier units, including cell structure
and function and body systems
 Health, microbes and disease
 The effects of ‘recreational’ drugs
C2 Responsible use of materials
Earth science
 The composition of the Earth and the
atmosphere; impact of humans
 The structure of the Earth; the rock
cycle
 Earth as a source of limited
resources
 The carbon cycle
Energy in matter
 Internal energy stored in materials
Energetics
 Exothermic and endothermic
chemical reactions (qualitative)
P2 Waves and auditing transfers
Light waves
 The similarities and differences
between light and waves in matter
 Light waves travelling through a
vacuum; speed; transmission
 Use of ray model
 Colour and frequencies of light
Energy and fuel
 Energy in a domestic context; in food
 Relationship between rate of transfer
and amount of energy used
 Heating and thermal equilibrium
Auditing change
 Energy as a quantity that can be
quantified and calculated
 Audit calculations using measures of
change in the energy
 Rates of change in W and kW
Please note this is an over view only, and subject to minor changes pre-publication.
©HarperCollinsPublishers 2013