Download App

4. d and f- block elements — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistry4. d and f- block elements1 Mark
MCQ
Which of the following pairs has the same size ?
  • A
    $Fe^{2+}, Ni^{2+}$
  • B
    $Zr^{4+}, Ti^{4+}$
  • ✓
    $Zr^{4+}, Hf^{4+}$
  • D
    $Zn^{2+}, Hf^{4+}$
✓

Answer

Correct option: C.
$Zr^{4+}, Hf^{4+}$
c
In general, the atomic and ionic radii increases on moving down a group but the elements of second transition series $(Zr, Nb, Mo)$ have almost same radii as the elements of third transition series $(Hf, Ta, W, etc)$. This is because of lanthanoid contraction, i.e.

imperfect shielding of one $4f \;e^{-}$ by another.

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

Explore more

More "M.C.Q (1 Marks)" from 4. d and f- block elements→4. d and f- block elements — all question types→Chemistry STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Which of the following does not show positive deviation from Raoult’s law
→
Which alkene is formed from the following reaction

$C{H_3}C{H_2}C{H_2}CH = PP{h_3} + 2 - $  Butanone

→
Among the following essential amino acid is:
→
$[Co_2(CO)_8]$ displays
→
A solution of urea contain $ 8.6\,gm/litre$ (mol. wt. $60.0$). It is isotonic with a $5\% $ solution of a non-volatile solute. The molecular weight of the solute will be
→
Which of the following pair of Amino acid are obtained during the hydrolysis of aspartame
→
The chief source of iodine in which it is present as sodium iodate is
→
Assertion : Magnetic moment values of actinides are lesser than the theoretically predicted values.

Reason : Actinide elements are strongly paramagnetic.

→
$4$ -chloro- $1$ -butanol $+ NaOH \to (B)$  Product $(B)$ of the above reaction is
→
The compound$(s)$ that exhibit$(s)$ geometrical isomerism is$(are)$

$(A)$ $\left[\mathrm{Pt}(\mathrm{en}) \mathrm{Cl}_2\right]$ $(B)$ $\left[\mathrm{Pt}(\mathrm{en})_2\right] \mathrm{Cl}_2$

$(C)$ $\left[\mathrm{Pt}(\text { en })_2 \mathrm{Cl}_2\right] \mathrm{Cl}_2$ $(D)$ $\left[\mathrm{Pt}\left(\mathrm{NH}_3\right)_2 \mathrm{Cl}_2\right]$

→