Question

Assertion : Mendeleev’s arranged elements in horizontal rows and vertical columns. Reason : Mendeleev’s ignored the order of atomic weight thinking that the atomic measurements might be incorrect.

Answer 1

Answer:

According to Mendeleev's periodic table, it was atomic weight on which all the properties depends upon.

It failed because of anomalous pairs, where the atomic weight of the first atom which is more is being arranged in the periodic table before that of the atom that has a smaller atomic weight.

These are called anomalous pairs.

Mendeleev's told that atomic weight keeps on increasing as we move in a periodic table but it violated the rule.

Hence, Assertion is incorrect, but reason is correct.

Hence option D is the cor

Answer 2

Answer:

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Explanation:

assertion is correct but reason is wrong

Mendeleev arranged basis of similarity of properties of elements