MCQ
Gadolinium has a low value of third ionisation enthalpy because of $......$
- ✓high exchange enthalpy
- Bhigh electronegativity
- Chigh basic character
- Dsmall size
✓
Answer
Correct option: A.
high exchange enthalpy
a
${ }_{64} Gd =[ Xe ] 6 s ^{2} 4 f ^{7} 5 d ^{1}$
${ }_{64} Gd =[ Xe ] 6 s ^{2} 4 f ^{7} 5 d ^{1}$
$Gd ^{+2}=[ Xe ] 4 f ^{7} 5 d ^{1}$
After losing $5 d$ electron $4 f$ has maximum exchange energy so Gd has low value of Third Ionisation energy
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Which of the following mixture is chromic acid
$Cu|Cu^{2+} (0.01\,M)||\, Cu^{2+}\,(0.1\,M)|\,Cu$
→$E_{cell} = $ ?
$H_2S$ is more acidic than $H_2O,$ due to
→Mass of $NaOH$ required for formation of $100\, ml$ of its decimolar solution is .............. $\mathrm{g}$
→$C_8H_{18}$ ($A$) on mono chlorination forms only one type of $C_8H_{17}Cl\ \ (B)$ Hence ($A$) can be
→Assertion : Addition of $NH_4OH$ to an aqueous solution of $BaCl_2$ in the presence of $NH_4Cl$ (excess) precipitates $Ba(OH)_2$.
Reason : $Ba(OH)_2$ is insoluble in water
→Reason : $Ba(OH)_2$ is insoluble in water
An acidic buffer solution can be prepared by mixing solution of
$17\,mg$ of a hydrocarbon (M.F. $C _{10} H _{16}$ ) takes up $8.40\,mL$ of the $H _2$ gas measured at $0^{\circ}\,C$ and $760\,mm$ of $Hg$. Ozonolysis of the same hydrocarbon yields $Image$ The number of double bond/s present in the hydrocarbon is $...........$.
→Out of the following which has smallest bond length
The atomic radii in periodic table among elements from right to left