A. DEVELOPMENT OF CHEMICAL ELEMENT PERIODICAL   SYSTEM

   

1. Lavoisier Element Classification

Antoine Lavoisier in 1869 defined element as an indivisible object. Lavoisier made a list of 33 chemical elements which was divided into gas, non-metal, and soil

2. Dobereiner Elements Classification

 

In 1817, Johann Wolfgang Dobereiner made a classification of the chemical elements. He made groups of every three chemical elements with similar properties (triad) base on its atomic weight rising and it is known as Dobereiner triad law

3. Chancourtois Elements Classification (Telluric Spiral de Chancourtois)

 

In 1862 , Alexander Beguyer de Chancourtois classified chemical elements based on its atomic weight rising. These chemical elements were developed into spiral shaped arrangement.

4. Newlands Elements Classification

 John Alexander Reina Newlands was recogonized for his idea of octave theory classification.

Newlands classified chemical element based on its atomic weight mounting. He found the linkage between element properties and atomic weight rising.

Element properties will be repeated after every eight elements (octave law)

5. Mendeleev and Meyer Periodic Table

In 1896, Dmitri Mendeleev dan Julius Lothar Meyer founded a new method to arrange chemical elements. Mendeleev and Meyer conducted their piece separately, but almost at the same time, they published nearly identical classification schemes.

a. Mendeleev Periodic Table

Mendeleev discovered that if the elements were arranged base on their atomic mass rising, then elements with similar properties will be arranged periodically. 

b. Meyer Periodic Table

Lothan Meyer arranged a nearly similar periodic table to Mendeleev periodic. Meyer put elements with the same valence in one column. Meyer’s idea was simpler than Mendeleev periodic table.

6. Moseley Elements Classification Method

Based on Rutherford’s findings, Henry Moseley studied X-ray and its correlation with the amount of electrical charge using X-ray spectroscopy. The result show linier trend that revealed the correlation between atomic number and atomic properties periodically.After that Moseley arranged the elements based on the increasing of atomic number in the periodic table form.

  Moseley periodic table succeeded in patching up Mendeleev periodic table weakness. Moseley periodic table was considered as modern periodic table until the middle of 20th century.