MCQ
Smallest ionic radius is:
  • A
    $La^{3+}$
  • B
    $U^{3+}$
  • $Yb^{3+}$
  • D
    $Cf^{3+}$

Answer

Correct option: C.
$Yb^{3+}$
Atomic and ionic radius of lanthanides decreases from $La$ to $Lu.$ Due to the contraction of lanthanide the decrease in ionic radius of the element in the lanthanide series from lanthanum to lutetium occurs.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

The vapour pressure of pure benzene and methyl benzene at $27^{\circ} \mathrm{C}$ is given as $80 \mathrm{Torr}$ and $24 \mathrm{Torr}$, respectively. The mole fraction of methyl benzene in vapour phase, in equilibrium with an equimolar mixture of those two liquids (ideal solution) at the same temperature is. . . . . . .$\times 10^{-2}$ (nearest integer)
$\mathop {{C_6}{H_6}O}\limits_{phenol} $ $\xrightarrow[\begin{subarray}{l} 
  3{H_2}(High\,\,temp \\ 
  and\,\,pressure) 
\end{subarray} ]{{Ni}}(A)\xrightarrow{{Cu}}(B)$ $\xrightarrow{{N{H_2}OH}}(C)\xrightarrow{{{H^ \oplus }}}$ $(D)\xrightarrow{{H{O^ - }}}(E)$

Product $(E) $ is

$KMn{O_4}$ acts as an oxidising agent in the neutral medium and gets reduced to $Mn{O_2}$. The equivalent weight of $KMn{O_4}$ in neutral medium
The increasing order of reactivity of the following compounds towards reaction with alkyl halide directly is
Which of following can be use to convert $3-$ methyl butan $-2-$ one in to isopentane
In the reaction $[X]$ will be :
Cerium $(Z = 58)$ is an important member of the lanthanoids. Which of the following statements about cerium is incorrect
Consider the following statements :-

$(i)$ Increase in concentration of reactant increases the rate of a zero order reaction

$(ii)$ Rate constant $k$ is equal to $'A'$ if $E_a = 0$

$(iii)$ Rate constant $k$ is equal to $'A'$ if $E_a = \infty$

$(iv)$ $log_e k$  vs  $T$ is a straight line

$(v)$ $log_ek$  vs   $1/T$ is straight line
Correct statement are

$0.5\,N$ solution of a salt placed between two platinum electrodes $2.0\,cm$ apart and of area of cross section $4.0\,cm^2$ has a resistance of $25\,ohms$ . Calculate the equivalent conductivity of solution ................. ${\Omega ^{ - 1}}{\rm{c}}{{\rm{m}}^2}{\rm{e}}{{\rm{q}}^{ - 1}}$
Phthalic acid reacts with resorcinol in the presence of concentrated $H_2SO_4$ to give