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What were the main demeris of mendeleev'...

What were the main demeris 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)

Text Solution

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The correct Answer is:
B
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Read the passage given below and answer the following questions: The d block elements are the 40 elements contained in the four rows of ten columns (3-12) in the periodic table. As all the d block elements are metallic, the term d-block metals is synonymous. This set of d-block elements is also often identified as the transition metals, but sometimes the group 12 elements (zinc, cadmium, mercury) are excluded from the transition metals as the transition elements are defined as those with partly filled d or fshells in their compounds. Inclusion of the elements zinc, cadmium and mercury is necessary as some properties of the group 12 elements are appropriate logically to include with a discussion of transition metal chemistry. The term transition element or transition metal appeared to derive from early studies of periodicity such as the Mendeleev periodic table of the elements. His horizontal table of the elements was an attempt to group the elements together so that the chemistry of elements might be explained and predicted. In this table there are eight groups labeled I-VIII with each subdivided into A and B subgroups. Mendeleev recognize properties of elements in Group VII are related those of some of the elements in Group VII and those at the start of the next row Group I. In that sense, these elements might be described as possessing properties transitional from one row of the table to the next. Assertion (A): Group VII elements of Mendeleev periodic table are transition elements. Reason (R): Group I -VIII in Mendeleev periodic table is divided into two subgroups, A and B.

Read the passage given below and answer the question: The d block elements are the 40 elements contained in the four rows of ten columns (3-12) in the periodic table. As all the d block elements are metallic, the term d-block metals is synonymous. This set of d-block elements is also often identified as the transition metals, but sometimes the group 12 elements (zinc, cadmium, mercury) are excluded from the transition metals as the transition elements are defined as those with partly filled d or f shells in their compounds. Inclusion of the elements zinc, cadmium and mercury is necessary as some properties of the group 12 elements are appropriate logically to include with a discussion of transition metal chemistry. The term transition element or transition metal appeared to derive from early studies of periodicity such as the Mendeleev periodic table of the elements. His horizontal table of the elements was an attempt to group the elements together so that the chemistry of elements might be explained and predicted. In this table there are eight groups labeled I-VIII with each subdivided into A and B subgroups. Mendeleev recognized that certain properties of elements in Group VIII are related to those of some of the elements in Group VII and those at the start of the next row Group I. In that sense, these elements might be described as possessing properties transitional from one row of the table to the next. (source: Winter, M. J. (2015). D- block Chemistry (Vol. 27). Oxford University Press, USA.) In the following question, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the choices on the basis of the above passage. Assertion : Group VII elements of Mendeleev periodic table are transition elements. Reason: Group I-VIII in Mendleev periodic table is divided into two subgroups, A and B.

Read the passage given below and answer the following questions: The d block elements are the 40 elements contained in the four rows of ten columns (3-12) in the periodic table. As all the d block elements are metallic, the term d-block metals is synonymous. This set of d-block elements is also often identified as the transition metals, but sometimes the group 12 elements (zinc, cadmium, mercury) are excluded from the transition metals as the transition elements are defined as those with partly filled d or fshells in their compounds. Inclusion of the elements zinc, cadmium and mercury is necessary as some properties of the group 12 elements are appropriate logically to include with a discussion of transition metal chemistry. The term transition element or transition metal appeared to derive from early studies of periodicity such as the Mendeleev periodic table of the elements. His horizontal table of the elements was an attempt to group the elements together so that the chemistry of elements might be explained and predicted. In this table there are eight groups labeled I-VIII with each subdivided into A and B subgroups. Mendeleev recognize properties of elements in Group VII are related those of some of the elements in Group VII and those at the start of the next row Group I. In that sense, these elements might be described as possessing properties transitional from one row of the table to the next. Assertion (A): Nickel is a transition element that belongs to group 10 and period 4 of the modern periodic table. Reason (R): Electronic configuration of Nickel is [Ar]_(18)3d^(8)4s^2

Read the passage given below and answer the question: The d block elements are the 40 elements contained in the four rows of ten columns (3-12) in the periodic table. As all the d block elements are metallic, the term d-block metals is synonymous. This set of d-block elements is also often identified as the transition metals, but sometimes the group 12 elements (zinc, cadmium, mercury) are excluded from the transition metals as the transition elements are defined as those with partly filled d or f shells in their compounds. Inclusion of the elements zinc, cadmium and mercury is necessary as some properties of the group 12 elements are appropriate logically to include with a discussion of transition metal chemistry. The term transition element or transition metal appeared to derive from early studies of periodicity such as the Mendeleev periodic table of the elements. His horizontal table of the elements was an attempt to group the elements together so that the chemistry of elements might be explained and predicted. In this table there are eight groups labeled I-VIII with each subdivided into A and B subgroups. Mendeleev recognized that certain properties of elements in Group VIII are related to those of some of the elements in Group VII and those at the start of the next row Group I. In that sense, these elements might be described as possessing properties transitional from one row of the table to the next. (source: Winter, M. J. (2015). D- block Chemistry (Vol. 27). Oxford University Press, USA.) In the following question, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the choices on the basis of the above passage. Assertion: Nickel is a transition element that belongs to group 10 and period 4 of the modern periodic table. Reason: Electronic configuration of Nickel is [Ar]_(18)3d^(8)4s^2

NCERT FINGERTIPS-CLASSIFICATION OF ELEMENTS AND PERIODICITY -Assertion And Reason
  1. What were the main demeris 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. Assertion:Oxidation state of oxygen in OF(2) and Na(2)O is +2 and -2 r...

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

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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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