Question

1. Which important property did Mendeleev use to classify the elements in his periodic table and did he stick to that?

Answer 1

The periodicity of a table depends on the atomic mass and did not stick to that property. He changed some series of element.

Answer 2

HÈLLØ!!

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$\Huge{\mathfrak{\orange{\underline{Answer}}}}$

▶️A Russian chemist, Dmitri Mendeleev was the first to develop a periodic table & he gave a law called Mendeleev periodic law which states that the physical & chemical properties of the elements are a periodic function of their atomic masses.

▶️On the basis of this law he developed a Mendeleev periodic table, where he arranged the elements in his periodic table ordered by atomic weight or mass.

▶️He arranged the elements in periods and groups in order of their increasing atomic weight.

▶️He placed the elements with similar properties in the same group.

▶️However, he did not stick to this arrangement for long.

▶️He found out that if the elements were arranged strictly in order of their increasing atomic weights, then some elements did not fit within this scheme of classification.

▶️Therefore, he ignored the order of atomic weights in some cases.

▶️For example, the atomic weight of iodine is lower than that of tellurium.

▶️Still Mendeleev placed tellurium (in Group VI) before iodine (in Group VII) simply because iodine’s properties are so similar tofluorine, chlorine, and bromine.

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THÅÑKẞ!!