S2 Science
Elements and Compounds
REVISION
NEW LEARNING
By contributing to investigations
into familiar changes in
substances to produce other
substances, I can describe how
their characteristics have changed.
SCN 2-15a
I have developed my
knowledge of the Periodic
Table by considering the
properties and uses of a
variety of elements relative
to their positions
SCN 3-15a
Periodic Table
Today we will learn to
State what elements are and where you can
find out information about them.
We will do this by
Look at the periodic table together to learn
how to find out information about elements.
Match elements to their uses
We will have succeeded if
Periodic Table
Find this page in your planner – you will be using it a lot!
Periodic Table
• This contains all of the elements that
we know of
• Elements are the simplest atoms, they
are used as the building blocks for
everything in life
• Elements can not be broken down into
anything simpler
In pairs…..
• Use the building blocks shown here to
build as many different towers as
possible
What about….
• Not so easy!!
• Like lego bricks the elements in the
periodic table can form many different
structures
Elements and Uses
• Work in pairs
• You will be given a set of cards, with
elements and what they are used for
• You have to work together to match up
the element to its use
Elements
There are five elements in the list below.
Underline them.
water
oxygen
silver
vinegar
zinc
salt
bread
air
neon
sugar
brass
carbon
Classifying Elements
Today we will learn to
Explain why the periodic table is arranged
the way that it is
We will do this by
Look at the periodic table together to learn
how to find out information about elements.
Match elements to their uses
We will have succeeded if
Periodic Table
Classifying elements
• Why do we have to put things in order?
• Think of something that you know that
is put into order
• A library is put into children's section
and adults section. There is also fiction
and non fiction.
Classifying elements
• In pairs
• Look at the element data cards. Put
them into groups depending on their
properties
• If they have similar properties they will
be in the same group
Chemistry trumps
• In groups of four
• Give each person in the group an equal
number of cards
• Play element trumps using the
information given about the elements on
the cards
Groups and Periods
Today we will learn to
Explain the difference between a group
and a period
We will do this by
Looking at the periodic table to see
where they are
We will have succeeded if
Groups and periods
Groups and periods introduction
Groups
• A group of elements will react in a
similar way
Brainiac video
Group 7 - Halogens
This group contains non-metals. They are
very reactive
1 2
8
3 4
5 6 7
Group 8 – Noble Gases
This group contains non-metals. They do not
react with other elements so are useful in their
own way. Can you think of uses?
1 2
8
3 4
5 6 7
Quick Quiz
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•
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•
What is group 1 called?
How does group 1 behave?
What is group 2 called?
How does group 2 behave?
What is group 7 called?
How does group 7 behave?
What is group 8 called?
How does group 8 behave?
Periods
• A period goes across the way in the
periodic table
Metals and Non-metals
• Elements can be divided into METALS and
NON-METALS.
• Most non-metals are non-conductors of
electricity.
• Carbon (in the form of graphite) is the only
non-metal which conducts electricity.
• Draw a line on your periodic table
• Metals are on the left hand side
Elements
• Each element is represented by a symbol.
• This symbol is made up of 1 or 2 letters.
• The symbol is unique to that element.
• The first letter is always a capital
• The second letter (if it has one) is always a
small letter
In Pairs…
• Write down the symbols for 5 different
elements
• Get your partner to find the names
• If you get confident you could time
each other!
In pairs
Use the periodic table to find the symbols
for the groups of elements below. Each
group should spell a different cartoon
character
• Tungsten, oxygen, oxygen, dysprosium
• Sulphur, cobalt, oxygen, boron, yetrium
Mixtures and Compounds
Today we will learn to
Describe what a mixture is, and how it is
different from a compound
We will do this by
Look at a mixture and learn how to separate it.
Watch this mixture being changed into a
compound and how this is different
We will have succeeded if
Mixtures
A mixture is formed by simply mixing
together two elements without chemically
joining together
Examples of mixtures:
Air
Skittles
Iron and Sulphur
• Look at the mixture of
iron and sulphur
• Try separating this
mixture
• What happens when you
heat this up? http://www.youtube.com/watch?v=A
5H6DVe5FAI
Mixtures
Filtration
This is a technique used to separate
insoluble solids from liquids
Mixtures
Filtration
Gas Tests
Today we will learn to
Explain how to test for common gases
We will do this by
Test these gases and note your
observations
We will have succeeded if
Gas Tests
Hydrogen
Carbon dioxide
Oxygen
Experiments
• Add 3ml of lime water into carbon
dioxide test tube. What happens?
• Put a glowing (just blown out) splint to
the neck of the oxygen test tube.
What happens?
• Put a lit splint to the neck of the
hydrogen test tube. What happens?
Gas
Oxygen
Hydrogen
Carbon
dioxide
Observations
Carbon dioxide
Carbon dioxide turns limewater cloudy
Carbon dioxide turns limewater cloudy
Hydrogen
Carbon dioxide turns limewater cloudy
Hydrogen burns with a “pop”
Carbon dioxide turns limewater cloudy
Hydrogen burns with a “pop”
Oxygen
Carbon dioxide turns limewater cloudy
Hydrogen burns with a “pop”
Oxygen re-lights a glowing splint
Mixtures and Compounds
• When two substances are mixed together
they can usually be separated easily
(mixture).
• When two substances join together in a
chemical reaction they form a compound.
• They cannot be separated easily.
• The two substances have joined together
with chemical bonds.
Compounds
What is a compound?
When atoms of different elements join
together in a chemical reaction they form a
new substance called a compound
This is different from a mixture, where the
atoms are just mixed together and not
chemically joined
Naming compounds
Compounds containing two elements end with
ide
e.g. lithium + chlorine = lithium chloride
Magnesium + oxygen = magnesium oxide
Which elements…
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Sodium fluoride
Lithium bromide
Calcium oxide
Aluminium chloride
Phosphorus sulphide
Caesium chloride
Naming compounds
Two exceptions: compounds containing two
element AND oxygen end in ite or ate
e.g.
copper, sulphur and oxygen = copper sulphate
Sodium, sulphur and oxygen = sodium sulphite
Which elements…
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Sodium nitrate
Lithium sulphate
Calcium phosphate
Aluminium chlorate
Phosphorus sulphite
Caesium nitrite
S2 starter
1. Name the compound formed when
copper and chlorine react together.
2. What elements are in copper sulphide?
3. What elements are in copper
carbonate?
4. What elements are in copper chloride?
5. What elements are in copper chlorite?
Breaking Compounds
Today we will learn to
Explain how to break compounds apart
We will do this by
Carrying out an experiment to break up copper
chloride
We will have succeeded if
Breaking Compounds
• If electricity is passed through a
compound it can be separated into the
elements it is made from.
• The diagram below shows the apparatus
used to do this.
carbon
rod
+
-
6v d.c power
pack
green liquid
(made from green powder
dissolved in water)
• The electric current is switched on.
Breaking compounds
• Aim:
To break up copper chloride using
electricity
• Results:
POSITIVE
carbon rod
NEGATIVE
carbon rod
• Conclusion:
Observations
Before the
experiment
After the
experiment
Breaking Compounds
• After a few minutes copper is deposited on
one carbon rod and chlorine gas given off at
the other.
+
chlorine
gas
Copper chloride
Compound
6v d.c power
pack
copper
copper
element
+
+
chlorine
element