MCQ
The correct order of the first ionization enthalpy is
  • A
    $\mathrm{Al}>\mathrm{Ga}>\mathrm{Tl}$
  • B
    $\mathrm{Ga}>\mathrm{Al}>\mathrm{B}$
  • C
    $\mathrm{B}>\mathrm{Al}>\mathrm{Ga}$
  • $\mathrm{Tl}>\mathrm{Ga}>\mathrm{Al}$

Answer

Correct option: D.
$\mathrm{Tl}>\mathrm{Ga}>\mathrm{Al}$
d
($i$) due to lanthanide contraction $\mathrm{T} \ell$ has more $I.E$. as compared to $\mathrm{Ga}$ and $\mathrm{A} \ell$

($ii$) due to scandide contraction Ga has more $I.E$. as compared to $\mathrm{A} \ell$

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 solubility product of sparingly soluble salt $A X_{2}$ is $3.2 \times 10^{-11}$. Its solubility (in $\left. mol / L \right)$ is
Which of the following is a lewis acid ?
Identify the pair of reactants that upon reaction, with elimination of HCl will give rise to the dipeptide Gly-Ala.
Image
Vessel-$1$ contains $w _2 g$ of a non-volatile solute $X$ dissolved in $w _1 g$ of water. Vessel-$2$ contains $w _2 g$ of another non-volatile solute $Y$ dissolved in $w _1 g$ of water. Both the vessels are at the same temperature and pressure. The molar mass of $X$ is $80 \%$ of that of $Y$. The van't Hoff factor for $X$ is $1.2$ times of that of $Y$ for their respective concentrations. The elevation of boiling point for solution in Vessel-$1$ is. . . . . .$\%$ of the solution in Vessel- $2$.
The bond order and magnetic behaviour of $\mathrm{O}_{2}^{-}$ion are, respectively:
One mole of potassium dichromate completely oxidises the following number of moles of ferrous sulphate in acidic medium
Which of the following will react faster through $S_{N} 1$ mechanism ?
Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at boiling point of water. Choose the correct option.
Given below are two statements

Statement $I :$ $o-$Nitrophenol is steam volatile due to intramolecular hydrogen bonding.

Statement $II :$ $o-$Nitrophenol has high melting due to hydrogen bonding.

In the light of the above statements, choose the most appropriate answer from the options given below

A sudden large jump between the values of second and third ionisation energies of an element would be associated with the electronic configuration