h7y3-2026-01-23_13_03_23-scanned-pages.pdf
h7y3-2026-01-23_13_03_23-scanned-pages.pdf
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LAW OF TRIADS
LAW OF TRIADS
An early chemical classification system stating that elements with similar properties could be grouped into triads, where the atomic mass of the middle element was the average of the first and third.
Johann Wolfgang Dobereiner
A German chemist who noticed that some elements liked to hang out in groups of three and called those "triads".
The elements in a triad shared similar physical and chemical properties.
The middle element's atomic mass was roughly the average of the other two.
Example: Calcium, Strontium, and Barium
The average of the two elements correspond to eighty-eight point seven, which is almost equal to the atomic mass of Strontium.
The Law of Triads doesn't work perfectly for all elements.