Download App

3. Classification of elements and periodicity in properties — Chemistry STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 ScienceChemistry3. Classification of elements and periodicity in properties1 Mark
MCQ
The first ionisation potentials $(eV)$ of $Be$ and $B$ respectively are :-
  • A
    $8.29\, eV, 9.32\, eV$
  • B
    $9.32\, eV, 9.32\, eV$
  • C
    $8.29\, eV, 8.29\, eV$
  • ✓
    $9.32\, eV, 8.29\, eV$
✓

Answer

Correct option: D.
$9.32\, eV, 8.29\, eV$
d
The first ionization potentials $(e V)$ of $B e$ and $B$ respectively are $9.32,8,29 .$

According to theory as we move from lest to right in a period the ionization potential should increase but in case of $B e$ and $B$ Beryllium is having more ionization potential than Boran due to completely filled s orbital in Beryllium $\left(1 s^{2} 2 s^{2}\right)$.

Hence option D is correct.

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 3. Classification of elements and periodicity in properties→3. Classification of elements and periodicity in properties — all question types→Chemistry STD 11 Science question papers→Rajasthan Board STD 11 Science question papers→Rajasthan Board question paper generator→

Similar questions

For $Na^+ , Mg^{2+}, F^-$ and $O^{2-}$; the correct order of increasing Ionic radii is
→
Which one of the following molecules is polar ?
→
In third row of periodic table from $Na$ to $Cl$
→
Order of first ionization potentials of elements $Li, Be, B, Na$ is
→
Which ion has largest radius
→
For the equilibrium

$SO_2Cl_2(g) \rightleftharpoons  SO_2(g) + Cl_2(g)$ , what is the temperature at which $\frac{{{K_p}(atm)}}{{{K_c}(M)\,}} = \frac{1}{3}$ ? ......$K$

→
The number of atoms in $4.25\, g$ of $NH_3$ is approximately
→
Which of the following involves transfer of five electrons ?
→
Addition of bromine to $1, 3-$butadiene gives
→
The boiling points of methanol, water and dimethyl ether are respectively $65\,^oC, 100\,^oC$ and $34.5\,^oC$. Which of the following best explains these wide  variations in $b.p.$?
→