If we break all materials down into the smallest particle that can exist by itself, then what we have is atoms. Atoms are the smallest particle of all matter that can exist by itself.

You can use

Internet site link

If you click on 'paper cutting` then there is an activity that can help you understand just how small atoms are.

Atoms are so small that we can not use cm or even mm to measure there size, we use nm (nanometers) 1nm = 0.000000001m

Example: The diameter of a sodium atom is 0.4nm. You could fit approximately 400000000000000000000000 of them on the surface of a 2 Euro piece.

There are three well known particles in the atom. The proton, neutron and electron. The table below gives the relative position, mass and charge of each particle.

The following sites have information and interesting facts about atoms.

Internet site link Has a atoms movie and quiz on atoms
Internet site link Shows how electrons orbit the nucleus of an atom

Go to Internet site link Go to GCSE stuff then the print out a copy of the periodic table can be downloaded from here. Acrobat reader is needed.

From the periodic table you will see that each element is represented in the following way:

where

We can use this information to calculate the number of protons neutrons and electrons found in each atom of a particular element.

Example

This represents the element carbon.

The number of neutrons is equal to A - Z

It is very useful to know the names and symbols of the common elements.

Internet site link Learn the elements and their symbols with these interactive games.

Link to homework activities.

• Introduction
• Information : Ions
• More Information
• Practical Work
• Homework Activities
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