Why are lanthanoid colored and paramagnetic L

1 Answer

Answer :

Ans It is due to presence of unpaired electrons, they are paramagnetic and they absorb light From visible region and undergoes f-f transition and radiate complementary colour . 

Related questions

Description : What is an lanthanoid contraction ? What is its cause ? Give its consequences .

Last Answer : Ans The decrease in atomic and ionic size with increase in atomic no. in lanthanoid series is called lanthanoid contraction . The cause of lanthanoid contraction is poor shielding effect of d and f ... is close resemblance between elements of 4 d and 5 d transition series . due to similar ionic 

Description : Why are Ti+2 and other transition metals and their ions paramagnetic ?

Last Answer :  Ans: These ions have unpaired electrons in d- subshell. 

Description : Explain the following , giving reason . (a) Transition metal and many of their compounds show paramagnetic behavior (b) The enthalpy of atomisation of the transition metal is high . (c) The Transition metal generally form coloured compounds . 

Last Answer : Ans(a) It is due to unpaired electrons . (b) It is due to strong metallic bond and additional Covalent bonds due to presence of unpaired electron in d- orbitals (c) It is due to presence of unpaired electrons ,they undergo d-d transition . 

Description : Why is Cu+1 diamagnetic and Cu +2 paramagnetic ?

Last Answer : It is because Cu+ does not have unpaired electrons where as Cu+2 has unpaired electrons in d-sub cell . 

Description : Why do transition metals have higher I.E than s –block elements ?

Last Answer : Ans: It is due to smaller atomic size than s-block elements , effective nuclear charge is more , terefore I.E is high.

Description : Why is K2Cr2O7 generally preferred over Na2Cr2O7 in a volumetric analysis .Give reason .

Last Answer : Ans : It is because Na2Cr2O7 is hygroscopic in nature that is why it absorbs moisture from atmosphere , therefore its standard solution can not be prepared .

Description : Why Mn+2 is more stable than Mn+3 but Fe +3 is more stable than Fe+2 ?

Last Answer : Ans Mn+2 has half filled d- orbital ,therefore it is more stable than Mn+3 Fe+3 has half filled d- orbital, therefore it is more stable than Fe +2 . 

Description : Why are transition metal fluorides are ionic in nature where as chlorides and bromides are covalent in nature . 

Last Answer : Ans - It is because of fluorine is most electronegative where as Cl and Br are less electro negative . Greater the difference in electro negativity more will be ionic character .

Description : Why do Zr and Hf show similar properties ?

Last Answer :  Ans It is due to similar ionic size which due to lanthanide contraction . 

Description : Why are Cr+ , Ag+ & Sc+3 Colour less ? 

Last Answer : Ans It is because they do not have unpaired electrons ,therefore can not under goes d-d transition .

Description : Why are transition metals and there compounds generally coloured ?

Last Answer : Ans It is due to present of unpaired electrons in transition metals and their ions , that is why they absorbed light from visible region and undergoes d-d transition and radiate complementary colour . 

Description : Why does V2O5 acts as catalyst ?

Last Answer : Ans : It is because V shows variable O.S . 

Description : Why Ce+3 Can be easily Oxidised to Ce+4 ?

Last Answer : Ans : It is because Ce+4 has stable electronic configuration . 

Description : Why do transition metals have high enthalpy of atomization ?

Last Answer :  Ans : it is due to strong metallic bonds and additional covalent bonds 

Description : What is the highest oxidation state shown by Cr. (24) , Mn(25) ?

Last Answer : Ans: Cr. Shows (+6) and Mn Shows (+7) Oxidation state .  

Description : Why are Zn , Cd , Hg are not regarded as transition metals ? 

Last Answer : Ans: It is because neither they nor their ions have incompletely filled d- orbitals . 

Description : What are d Block Elements ? 

Last Answer : Ans: Those elements in which d-orbital are progressively filled up are known as d-orbital.

Description : Application of d- & f- block elements

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Description : Lanthanoid contraction will not have any influence when we compare size of :-

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Description : [Fe(H2O)6]3+ is strongly paramagnetic whereas [Fe(CN)6]3- is weakly paramagnetic. Explain. (At. no. Fe = 26) -Chemistry

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Description : How is paramagnetic character of a compound is related to the no. of unpaired electrons?

Last Answer : Ans. Greater the number of unpaired electrons greater will be the paramagnetic character

Description : Which forms of Sulphur show paramagnetic behaviour ?

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Description : What is the relative permeability of a paramagnetic material? -General Knowledge

Last Answer : The answer is 'Greater than unity'

Description : A hydrogen atom is paramagnetic. What is a hydrogen molecule? -Do You Know?

Last Answer : answer:

Description : What is the relative permeability of a paramagnetic material? -General Knowledge

Last Answer : answer:

Description : What is paramagnetic ?

Last Answer : Substances that are weakly attracted by a magnetic field are called paramagnetic. Any substance that has odd or unpaired electrons in its atom ; They tend to be paramagnetic. This is because the rotation or spinning of unpaired electrons in an atom causes a magnetic moment.

Description : What is Paramagnetic Material ?

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Description : Among the following , the paramagnetic compound is

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Description : The pair(s) of reagents that yield paramagnetic species is/are

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Description : The pair(s) of reagents that yield paramagnetic species is/are

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Description : The metal carbonyl which is paramagnetic is

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Description : Which one of the following has lowest value of paramagnetic behaviour?

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Description : The pair(s) of reagents that yield paramagnetic species is/are

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Description : Is niobium paramagnetic?

Last Answer : Yes, niobium is a paramagnetic metal.

Description : Is niobium paramagnetic?

Last Answer : Yes, niobium is a paramagnetic metal.

Description : Which theory explains the paramagnetic nature of oxygen ? Who proposed it ?

Last Answer : Molecular orbital theory, proposed by Hunds and Mulliken

Description : A hydrogen atom is paramagnetic. What is a hydrogen molecule?

Last Answer : Diamagnetic

Description : What is the relative permeability of a paramagnetic material?

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Description : Nickel is a __________ material. (A) Ferromagnetic (B) Diamagnetic (C) Paramagnetic (D) None of these

Last Answer : (A) Ferromagnetic