Advertisements
Advertisements
प्रश्न
Compare the chemistry of actinoids with that of the lanthanoids with special reference to atomic and ionic sizes.
Compare the chemistry of actinoids with that of the lanthanoids in reference to atomic and ionic sizes.
Advertisements
उत्तर
Both lanthanoids and actinoids show a decrease in the size of their atoms or ions in the +3 oxidation state. In lanthanoids this decrease is called lanthanoid contraction, while in actinoids it is called actinoid contraction. However, in actinoids, the contraction increases gradually due to the very low shielding effect of 5f-electrons from one element to another.
APPEARS IN
संबंधित प्रश्न
What are lanthanoids?
What are the different oxidation states exhibited by the lanthanoids?
The chemistry of the actinoid elements is not so smooth as that of the Lanthanoids. Justify this statement by giving some examples from the oxidation state of these elements.
Name the members of the lanthanoid series which exhibit +4 oxidation state and those which exhibit +2 oxidation state. Try to correlate this type of behavior with the electronic configurations of these elements.
What are the consequences of lanthanoid contraction?
Name an element of lanthanoid series which is well knwon to shown +4 oxidation state. Is it a strong oxidising agent or reducing agent?
What is lanthanoid contraction? Write the.............
What is Lanthanoid contraction?
Although +3 is the characteristic oxidation state for lanthanoids but cerium also shows +4 oxidation state because:
(i) it has variable ionisation enthalpy
(ii) it has a tendency to attain noble gas configuration
(iii) it has a tendency to attain f 0 configuration
(iv) it resembles Pb4+
On the basis of Lanthanoid contraction, explain the following:
Stability of the complexes of lanthanoids.
The titanium (Z = 22) compound that does not exist is:-
In lanthanoid the last electron enters (n - 2)f subshell where n is equal to ______.
Zr (Z = 40) and Hf (Z = 72) have similar atomic and ionic radii because of ______.
Mischmetal is an alloy consisting mainly of ______.
Cerium (Z = S8) is an important member of lanthanoids. Which of the following statements about cerium is incorrect?
State a reason for the following:
La(OH)3 is more basic than Lu(OH)3.
Assertion: There is a continuous increase in size among Lanthanoids with an increase in atomic number.
Reason: Lanthanoids do not show Lanthanoid contraction.
Name an important alloy which contains some of the lanthanoid metals.
