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Since its birth in 1869, the Mendeleev p...

Since its birth in `1869`, the Mendeleev periodic table has been discussed and revised many times. Spectroscopic and other discoveries have filled in the blanks left by Mendeleev and added a new column consisting of the noble gases. Finally, Mendeleevs' periodic table was discovered because it did not provide any place for

A

tullotrups

B

isotopes

C

polymorphs

D

all of these

Text Solution

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The correct Answer is:
B
According to Mendeleev's classification, isotopes having different atomic masses should be placed differently, but it was never achieved in the table.
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Comprehension given below is followed by some multiple choice questions. Each question has one correct option. Choose the correct option. In the modern periodic table, elements are arranged in order of increasing atomic numbers which is related to the electronic configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four blocks, viz s, p, d and f. The modern periodic table consists of 7 periods and 18 groups. Each, period begins with the filling of a new energy shell. In accordance with the Aufbau principle, the seven periods (1 to 7) have 2, 8, 8, 18, 18, 32 and 32 elements respectively. The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthonoids and actinoids are placed at the bottom of the main body of the periodic table (ii) The last element of the p-block in 6th period is represented by the outermost electronic configuration.

R SHARMA-CLASSIFICATION OF ELEMENTS AND PERIODICITY IN ELEMENTS-Follow-up Test
  1. The position of hydrogen in Mendeleev's periodic table is not fixed bu...

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  2. In Mendeleev's table, although most of the elements were placed in the...

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  3. Since its birth in 1869, the Mendeleev periodic table has been discuss...

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  4. The empirical evolution of the periodic table reached its peak in 1913...

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  5. Which of the following gives a straight line?

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  6. Which of the following correctely describes Moseley's law?

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  7. Moden periodic law states that the properties of the elements are peri...

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  8. The physical and chemical properties of the elements denpend upton the...

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  9. The cause of periodicity in properties of the elements is the repetiti...

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  10. Which of the following numbers are called magic numbers?

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  11. The short form of the modern periodic table of the elements (also call...

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  12. In the modified Mendeleev's periodic table, the 18 vertical columns we...

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  13. In the short form of the modern periodic table, the period number corr...

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  14. In the short form of the modern periodic table, the first period conta...

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  15. In the short from of the modern periodic table,elements of both sixth ...

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  16. The naming of the new elements had been traditionally the privilege of...

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  17. Unnilennium is the systematic name for element having atomic number

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  18. Which of the following elements have been duly synthesized and officia...

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  19. What would be the IUPAC name and symbol for the element with atomic nu...

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  20. Total number of element in each period is twice the number ofbeing fil...

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