Introduction to and definition of the concept 'Element"
the elementary substances of matter
Of these building bricks, there are not even a hundred different ones in Nature.
On of the first things that you must know are the symbols of these elements.
Of course you can find the symbols in tables, but even the simplest chemistrty student must know a good number of them by heart.
For example, who does not know H2O, water, built up of two elements: H (Hydrogen) and O(Oxygen)?
Then you must know that you can classify all the elements in the so called Periodic Table, where every element has its own specific position.
That position has to do with what we met in module 01: the valency electrons and the number of main levels per atom.
You will see that the Periodic Table has four blocks: s, p, d or f (see further in this module)
This Periodic Table (PT) has a simple version, not including all elements.
This simple PT contains only the blocks s and p, in the so called main levels. The position of every element in the PT can be determined with the electronic structure of the element.
Just to have an idea you can go to websites about the PT and the elements in it. For example (in dutch, but find yourself an english version please):
every element on its place
In this module 02 you will read about the history of some elements.
Consider the elements as building bricks of matter, as elementary substances, every type having its own type of atom.
You must be capable to determine the place of an element in the PT (in the simple PT and in the complete PT)if you know the electronic structure of the atom.
Besides that, you will learn something in this module about the concept 'electronegativity'.
that is a very important concept in understanding some properties of substances.
Here you must think of the chemical bonds that such an element will realise (see also module 03).
You will learn to read and interpretate tables and graphics in this module.
Of course we will talk about metals and non metals. The difference between an element and a compound will be seen later, in module 05.
Lets try a definition of an element:
The chemical element is a substance that with chemical means
no longer can be decomposed in other substances.
Every element has its own atom number and an own symbol
Every symbol is a capital letter, sometimes followed by a small letter