1. Atoms Elements and Compounds

2. Atoms and Elements
Everything is made up of tiny particles called atoms
Atoms are tiny the tiniest speck you can see contains millions of atoms!
Molecular Expressions: Science, Optics and You - Secret Worlds: The Universe Within - Interactive Java Tutorial

3. Elements
When a substance is made of only 1 type of atom it is called an element
For example Copper is only made of Copper atoms it can’t be broken into anything simpler

4. The periodic Table of elements
This is a table of all the types of elements found on earth
Anything that exists is either one of these elements or a mixture of them!
Element Song
Do you recognise any of these elements?

5. Definitions
An atom is the smallest part of an element that still has the properties of that element
An Element is a substance that cannot be broken down into simpler substances by chemical means

6. Some common elements
Carbon – A solid that can have 2 forms, grey graphite or pencil “lead” or the gemstone Diamond! It is not a metal

7. Sulfur - a yellow solid non metal, it makes matches and gunpowder

8. ery
Iron – A hard silvery grey solid metallic element it is very common and is used to make ships, cars, skyscrapers etc.

9. Silver – a bright grey solid metal used to make jewellery and ornaments

10. Gold – A heavy, precious yellow metallic element, used for jewellry

11. Sodium – A soft, silver white metallic element that is very reactive
Sodium – A soft, silver white metallic element that is very reactive! It is used in street lighting as it glows yellow when burned

12. Symbols of Elements
Each element has its own chemical symbol, usually it is the initial of the element eg, H for Hydrogen, but sometimes the symbols come from Latin eg. Na for Sodium
The first letter is always a capital
The second letter if there is one is always a small letter

14. Compounds
There are only about 100 elements but we know there are hundreds of thousands of other substances such a s salt, water, plastic, carbon dioxide , sand etc.
These substances are made of 1 or more elements chemically combined together
Water is H2O this means Hydrogen and Oxygen chemically combined together

15. Definition
A compound is made when two or more elements combine together chemically

16. Making a compound
If we burn 2 elements such as iron and sulphur together we can get a completely new substance called Iron Sulphide
Look at the properties of iron and sulphur before they are chemically combined

17. If the iron and sulphur are mixed together the iron can be separated using a magnet
When they are chemically combined the iron is no longer magnetic!
A compound is a completely new substance with its own properties

18. Think of Water
Water is made of Hydrogen which is an explosive gas and oxygen which is needed to burn things yet when they combine to form H2O you get a liquid that can put out fires!

19. Molecules A compound is made up of molecules
1 H2O is a molecule of water
Carbon Dioxide gas is CO2 what type of atoms are in a molecule of Carbon Dioxide?
Answer

20. Big Molecules Some molecules are very big and contain lots of atoms
A molecule of sugar is C12H22O11
This means that 1 molecule of sugar has 12 carbons, 22 hydrogens and 11 oxygens!

21. Small Molecules
Some molecules are very small Hydrogen gas is made of H2 molecules which is 2 hydrogen atoms

22. Definition
A molecule is the smallest part of an element or compound that can exist on its own

23. Fixed amounts
The atoms that make a compound are present in definite fixed amounts
For example water will always have 2 hydrogens and one oxygen in a molecule
Salt NaCl will always have one sodium and one Chlorine in a molecule