Chemistry - C3 - History of the Periodic Table

HISTORY OF THE PERIODIC TABLE

In the EARLY 1800s - it was only possible to calculate atomic mass.

Newlands Law of Octaves - 1864

Arranged by ATOMIC MASS

Some patterns were identified - Alkali Earth Metals and Alkalis.

Messed up with Transition Metals - didnt get it right.

Mixed up metals and non metals.

Some groups didnt have similar properties.

NO GAPS WERE LEFT.

Dmitri Mendeleev - 1869

Arranged by both ATOMIC MASS & PROPERTIES

GAPS WERE LEFT TO KEEP SIMILAR PROPERTIES TOGETHER AND FOR UNDISCOVERED ELEMENTS. This was proven when the predicted elements were discovered, and…