GCSE AQA Chemistry The Periodic Table

The Periodic Table

The elements in the periodic tabl are arranged in order of atomic number and so that elements with similar properties are in columns, known as groups. This table is called a periodic table because similar properties occur at regular intervals. 

Elements in the same group of the periodic table have the same number of electrons in their outer shell and this gives them similar chemical properties. 

Developement of the periodic table:

Before the discovery of subatomic atoms, scientists attempted to classify elemts by arranging them in order of their atomic weight. The early periodic tables were incompleate and some elements were placed in inappropriate groups. 

In 1864 John Alexander Reina Newlands created the 'law…