atoms elements and compounds
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Atoms Elements and Compounds. 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. - PowerPoint PPT PresentationTRANSCRIPT
Atoms Elements and Compounds
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
Atoms and 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
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?
The periodic Table of elements
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
Definitions
Carbon – A solid that can have 2 forms, grey graphite or pencil “lead” or the gemstone Diamond! It is not a metal
Some common elements
Sulfur - a yellow solid non metal, it makes matches and gunpowder
Iron – A hard silvery grey solid metallic element it is very common and is used to make ships, cars, skyscrapers etc.
ery
Silver – a bright grey solid metal used to make jewellery and ornaments
Gold – A heavy, precious yellow metallic element, used for jewellry
Sodium – A soft, silver white metallic element that is very reactive! It is used in street lighting as it glows yellow when burned
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
Symbols of Elements
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
Compounds
A compound is made when two or more elements combine together chemically
Definition
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
Making a compound
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
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!
Think of Water
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
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!
Big Molecules
Some molecules are very small Hydrogen gas is made of H2 molecules which is 2 hydrogen atoms
Small Molecules
A molecule is the smallest part of an element or compound that can exist on its own
Definition
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
Fixed amounts