Periodic Table History

Our modern-day periodic table would not be what it is if it weren't for the contributions made by a few scientists in the 1800's.

The first one was William Odling.


William Odling

    

Odling seperated the 52 discovered elements into 13 groups based on their physical and chemical properties.

But new discoveries were being made and from 1863-1866, John Newlands stated that if hydrogen had a mass of 1, then every 8th element had common properties, which was named "the Law of Octaves".


John Newlands


But this was not the end of the periodic table. Our modern periodic table is based on the work of Dmitri Mendeleev, who arranged the elements by their masses and properties.  He found that properties of elements recur periodically. So he split his table into periods and groups (or families).  He made very accurate predictions on the undiscovered elements, which is why he left gaps in his table.


Dmitri Mendeleev

In the modern periodic table as shown below, the elements are arranged by atomic number, not by atomic mass as it was before.


Modern Periodic Table

You can see that the table is split up into the following sections:
1) Alkali metals
2) Alkaline earth metals
3) Lanthanoids
4) Actinoids
5) Noble gases
6) Other non-metals and
7) Poor metals

As you will notice, hydrogen is in its in group. This is because hydrogen behaves unlike any other element, although it has characteristics of groups 1 and 17.


There are other ways of displaying the periodic table, like this:


Circular Periodic Table

If you click here, you'll find some more useful information on the background of the periodic table.