S2 Science Elements and Compounds REVISION By contributing to investigations into familiar changes...
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Transcript of S2 Science Elements and Compounds REVISION By contributing to investigations into familiar changes...
S2 ScienceElements and Compounds
REVISION
By contributing to investigations into familiar changes in substances to produce other substances, I can describe how their characteristics have changed.SCN 2-15a
NEW LEARNING
I have developed my knowledge of the PeriodicTable by considering the properties and uses of a variety of elements relativeto their positions
SCN 3-15a
Periodic Table
Today we will learn toState what elements are and where you
canfind out information about them.
We will do this byLook at the periodic table together to
learnhow to find out information about
elements. Match elements to their uses
We will have succeeded if
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
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 toExplain why the periodic table is
arrangedthe way that it is
We will do this byLook at the periodic table together to
learnhow to find out information about
elements. Match elements to their uses
We will have succeeded if
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 toExplain the difference between a
groupand a periodWe will do this byLooking at the periodic table to seewhere they areWe will have succeeded if
Groups and periods
Groups and periods introduction
Group 8 – Noble GasesThis group contains non-metals. They do
notreact with other elements so are useful in
theirown way. Can you think of uses?
1 2
543 6 7
8
Quick Quiz
• 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?
• 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.
Metals and Non-metals
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
MgO
HeHg
C
Fe
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 toDescribe what a mixture is, and how it isdifferent from a compound
We will do this byLook at a mixture and learn how to separate
it. Watch this mixture being changed into acompound and how this is different
We will have succeeded if
MixturesA 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
Gas Tests
Today we will learn toExplain how to test for common gasesWe will do this byTest these gases and note yourobservationsWe will have succeeded if
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?
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…
• 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…
• 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 toExplain how to break compounds apart
We will do this byCarrying out an experiment to break up
copperchloride
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.
+-
green liquid(made from green powder dissolved in water)
6v d.c power pack
carbon rod
• The electric current is switched on.
Breaking compounds
• Aim:To break up copper chloride using
electricity
• Results:
• Conclusion:
Observations
Before the experiment
After the experiment
POSITIVE carbon rod
NEGATIVE carbon rod