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Why actinoid contraction is more than la...

Why actinoid contraction is more than lanthanoid contraction

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### Step-by-Step Solution: 1. **Understanding Contraction**: - Contraction in the context of the actinoids and lanthanoids refers to the decrease in ionic radii as we move across the series of elements. This is due to the increasing positive charge of the nucleus which pulls the electrons closer. 2. **Identify the Elements**: - The lanthanoid series consists of elements from Lanthanum (La) to Lutetium (Lu), while the actinoid series consists of elements from Actinium (Ac) to Lawrencium (Lr). ...
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Assign reasons for the following : (i) Cu(I) ion is not known to exist in aqueous solutions. (ii) Transition metals are much harder than the alkali metals. (iii) From element to element, actinoid contraction is greater than the lanthanoid contraction.

Assign reasons for the following : (i) The enthalpies of atomisation of transition elements are high. (ii) The transition metals and many of their compounds act as good catalyst. (iii) From element to element the actinoid contraction is greater than the lanthanoid contraction. (iv) The E^(@) value for the Mn^(3+)//Mn^(2+) couple is much more positive than that for Cr^(3+)//Cr^(2+) . (v) Scandium (Z = 21) does not exhibit variable oxidation states and yet it is regarded as transition element.

What is meant by 'lanthanoid contraction'?

Reason of lanthanoid contraction is

Lanthanide contraction is observed in:

Actinoid contraction is greater from element to element than lanthanoid contraction Why?

The gradual decrease in size (actionoid contraction) is from element to element is greater among the actinoids than that among the lanthanoids (lanthanoid contraction).

The effect of lanthanoid contraction in the lanthanoid series of elements by and large means :

(a) Complete the following chemical equations for reactions : (i) MnO_(4(aq))^(-) + S_(2)O_(3(aq))^(2-) + H_(2)O_((l)) to (ii) Cr_(2)O_(7 (aq))^(2-) + H_(2)S_((g)) + H_((aq))^(+) to (b) Give an explanation for each of the following observations : (i) The gradual decrease in size (actinoid contraction) from element to element is greater among the actinoids than that among the lanthanoids (lanthanoid contraction.) (ii) The greatest number of oxidation states are exhibited by the members in the middle of a transition series. (iii) With the same d-orbitals configuration (d^(4)) Cr^(2+) ion is a reducing agent but Mn^(3+) ion is an oxidising agent .

Give an explanation for each of the following observations: (i) The gradual decrease in size (actinoid con-traction) from element to element is greater among the actinoids than that among the lanthanoids (lanthanoid contraction). (ii) The greater number of oxidation states are exhibited by the members in the middle of a transition series. (iii) With the same d-orbital (d^4) , Cr^(2+) ion is a reducing agent but Mn^(3+) ion is an oxidising agent.

AAKASH INSTITUTE ENGLISH- ALCOHOLS, PHENOLS AND ETHERS-Assignment Section -D (Assertion - reason type question)
  1. Why actinoid contraction is more than lanthanoid contraction

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  2. Assertion : Boiling point of p-nitrophenol is greater than that of o-n...

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  3. A : When C(2) H(5) - O- CH(3) is reacted with one mole of Hl then C(2...

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  4. A : When 3,3-dimethyl butan - 2 - ol is heated in presence of concentr...

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  5. A : In esterification reaction , HCOOH is the most reactive acid among...

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  6. A : Ethers can't be distilled upto dryness due to fear of explosion . ...

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  7. Phenol is less acidic than........... .

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  8. A : CH(3) - underset(O)underset(||)(C)-COOH gives haloform reaction ...

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  9. A : Diphenyl ether is prepared by Williamson synthesis . R : This...

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  10. A : Grignard's reagent is prepared in the presence of ether . R :...

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  11. A : CH(3) - underset(CH(3))underset(|)overset(CH(3))overset(|)(C)-CH=...

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  12. A : Two moles of Grignard reagent is consumed in the formation of ter...

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  13. A : bond angle in ether is slightly greater than normal tetrahedral an...

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  14. A : CH(3)-underset(CH(3))underset(|)overset(CH(3))overset(|)(C)-O-CH...

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  15. A : Ortho - cresol is weaker acidic than meta-cresol . R : It is d...

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  16. A : Among all ortho halophenol , fluorophenol is least acidic . R ...

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  17. A : In esterification reaction alcohol act as nucleophile . R : ...

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  18. A : Phenol is manufactured by Dow 's pocess. R : It involves the ...

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  19. A : Primary alcohol is prepared by the reaction of primary amine with ...

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  20. A : The reactivity order of alcohols is 1^(@) gt 2^(@) gt 3^(@) for ...

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  21. A : The dehydration of ethyl alcohol in presence of Al(2)O(3) at 633 ...

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