Atoms and elements
All matter is made up of particles called atoms. They are too small to be seen and cannot be seen even with the most powerful microscope. There are huge numbers of atoms in the dot at the end of this sentence.
There are different types of atoms. There are about 100 different elements and each one has its own name and a particular chemical symbol by which it can be represented. Atomic symbol is either a capital letter or a capital letter and a small letter. Most atomic symbols are taken from the name of the element.
However, an element is made up of atoms which are all the same. For example, a piece of pure iron contains only iron atoms, and a test tube containing pure oxygen would only contain oxygen atoms.
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