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What were the main demerits of Mendeleev...

What were the main demerits of Mendeleev's periodic table?
(i)Hydrogen has been places in group I though it resembles to group VII as well
(ii)Position of some elements was not justified
(iii)Isotopes were not given separate places.
(iv)Lanthanides and actinides were not included in the table.

A

(i),(ii) and (iii)

B

(i),(ii),(iii)and (iv)

C

(ii)and(iv)

D

(i),(iii) and (iv)

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The correct Answer is:
B
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NCERT FINGERTIPS ENGLISH-CLASSIFICATION OF ELEMENTS AND PERIODICITY -Assertion And Reason
  1. What were the main demerits of Mendeleev's periodic table? (i)Hydrogen...

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  2. Assertion:According to mendeleev,the properties of elements are a peri...

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  3. Assertion:Atomic number is a more fundamental property of an element t...

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  4. Assertion:Atomic number of the element ununtrium is 113. Reason:Accor...

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  5. Assertion:In the present form of periodic table,the period number corr...

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  6. Assertion:The chemistry of the early actinoids is more comlicated than...

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  7. Assertion:The atomic size generally increases across a period and decr...

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  8. Assertion:Among isoelectronic species,the cation with the greater posi...

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  9. Assertion:On moving down the group the group,ionization enthalpy decre...

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  10. Assertion:For the elements O or F,the electron gain enthalpy is less n...

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  11. Assertion: Shielding effect increases as we go down the group. Reaso...

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  12. Assertion:Electronegativity is not a measurable quantity. Reason:The e...

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  13. Oxidation state of oxygen in OF(2) and Na(2)O is +2 and -2 respectivel...

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  14. Assertion:Boron can only form [BF(4)]^(-),whereas aluminium forms[AlF(...

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  15. Assertion:Metallic character is highest at the extremely left side of ...

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  16. Assertion:Na(2)O is basic whereas Cl(2)O(7) is acidic oxide. Reason:E...

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