p12-13 of IGCSE Chemistry Textbook:
Elements:
- A substance that cannot be broken down into a simpler substance
- Only one kind of atom can be found in an element
- Elements are listed in the Periodic Table
Out of the 117 elements that have been identified, 24 are artificially made and 91 elements occur naturally
Classification
- Elements are classified by their properties
- eg. metals and non-metals
Metals:
Many of them have....
- High densities
- High melting and boiling points
Non-metals:
Many of them have....
- Low densities
- Low melting and boiling points
Atoms:
- They are the building blocks of life
- 'Everything is made up of billions of atoms.
- Atoms are very small... (MINUSCULE)
- They are too small to be seen
- Smallest atom known is HYDROGEN
- Each HYDROGEN atom is represented as a sphere
- The sphere has a diameter of 0.000 000 07mm (7╳10-8)
- Atoms of different elements have different diameters and masses
More about Atoms can be found on the 'Atoms Page'
links to all the other subtopics can be found here.