Chemistry - The Periodic Table

  • Created by: Harneet
  • Created on: 06-05-13 12:57

Early Periodic Table

Many different people attempted to class all of the elements in an order, but lots of them failed in this attempt. Dimitri Mendeleev is usually regarded as the founder of the modern periodic table. John Newlands, and the Mendeleev attempted to classify the elements by arranging them in order of their atomic weights. this list can be arranged in a table so that the elements with similar properties are in columns, known as groups. the table is called a periodic table because similar properties occur at regular intervals. 

The early periodic tables were incomplete and some elements were placed in inappropriate groups if the strict order of atomic weights was followed. Mendeleev overcame some of the problems by leaving gaps for elements that he thought had not been discovered. 

Modern Periodic Table

When electrons, protons and neutrons were discovered early in the 20th century, the periodic table was arranged in order of atomic (proton) numbers. When this was done, all elements were placed in appropriate groups. 

The modern periodic table can be seen as an arrangement of the elements in terms of their 


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