Question

the three elements were written in the order of increasing atomic mass the atomic mass of middle element was roughly the averageof the atomic masses of other two elements that law was stated by​

Answer 1

Answer:

Dobereiner's Triad - definition

He found that the atomic mass of the middle element was approximately equal to the arithmetic mean (average) of the atomic masses of the other two elements of that triad when they are arranged in their increasing order of atomic mass, e.g., Li, Na, K.

Answer 2

Answer:

atomic mass

Explanation:

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