Question

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Answer 1

Explanation:

the average of atomic weight of 1st and 3td elements is the atomic weight of middle element. 2. the physical and chemical properties of element is the periodic functions of atomic number

Answer 2

Answer:

1-Dobereiner's law of triads states that, the atomic mass of the middle element of a triad is the arithmetic mean of the atomic masses of the other two elements. Example:In the triad of lithium, sodium and potassium

2-The modern periodic law states that the physical and chemical properties of the elements are the periodic functions of their atomic numbers. Scientists arranged elements in increasing order of their atomic numbers from left to right across each row

3)newland law of octate states that every eight element if arranged according to their atomic mass has same properties

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