Question

when mandle classify elements​

Answer 1

this theory came to light in the year 1829. according to the theory,the classification was made in such a way that each group consisted of three elements such that they owned the same properties.also,in each case,the atomic weight of the middle elements is supposed to be the arithmetic mean of the other two elements.

however,this theory suffered a major limitation as dobereiner could classify only 9 elements in such manner, out of all that were known at the time.therefore, new theories had to be introduced...

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