جميع المواضيع المتعلقة بـ ‘Dobereinier’

 

Dobereinier’s law of tirade

Dobereinier’s law of tirade

In 1817 Dobereiner found that when elements are arranged in the order of increasing atomic masses, groups of three elements (known as triads) having similar chemical properties are obtained. The atomic mass of the middle element was found to be the average of the rest of the two :

 

Li                  Na                  K

7                   23                  39

Na = (7 +…

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The Periodic Table

Elements can be grouped into classes according to the chemical compounds they form. If the elements are written in a table in order of increasing atomic weights, they fall naturally into a series of columns, with members of a given chemical group in the same column. This is called the periodic table of the elements.The term periodic means recurring at regular intervals. The original periodic tables were…

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