Question:
The correct order of metallic radius of Al, Ga, In, Tl is
The correct order of metallic radius of Al, Ga, In, Tl is
Show Hint
Remember anomaly: Gallium is slightly smaller than aluminium because of d-block contraction.
Updated On: Jun 15, 2026
- \(Tl& gt;In& gt;Al& gt;Ga\)
- \(Tl& gt;In& gt;Ga& gt;Al\)
- \(In& gt;Ga& gt;Al& gt;Tl\)
- \(Ga& gt;In& gt;Tl& gt;Al\)
Show Solution
Verified By Collegedunia
The Correct Option is A
Solution and Explanation
Concept:
Normally atomic radius increases down group.
However due to d-block contraction and f-block contraction anomalies occur.
Group 13 elements:
\[
Al,Ga,In,Tl
\]
Expected increase downward but gallium becomes smaller than expected due to poor shielding by d electrons.
Step 1: Observe periodic trend. Normally \[ Al& lt;Ga& lt;In& lt;Tl \] But d-block contraction affects gallium. Its size becomes slightly smaller than aluminium.
Step 2: Apply d-block contraction effect. Gallium has filled 3d electrons. These electrons shield poorly. Effective nuclear charge increases. Radius decreases. Thus \[ Ga& lt;Al \]
Step 3: Final order. Thus order becomes \[ Tl& gt;In& gt;Al& gt;Ga \] Correct option: \[ \boxed{A} \]
Step 1: Observe periodic trend. Normally \[ Al& lt;Ga& lt;In& lt;Tl \] But d-block contraction affects gallium. Its size becomes slightly smaller than aluminium.
Step 2: Apply d-block contraction effect. Gallium has filled 3d electrons. These electrons shield poorly. Effective nuclear charge increases. Radius decreases. Thus \[ Ga& lt;Al \]
Step 3: Final order. Thus order becomes \[ Tl& gt;In& gt;Al& gt;Ga \] Correct option: \[ \boxed{A} \]
Was this answer helpful?
0
0
Top TS EAMCET Chemistry Questions
- A, B and C are three biomolecules. The results of the tests performed on them are given below :A, B and C are respectively :
Molisch's lest Barfoed Test Biuret Test A Positive Negative Negativde B Positive Positive Negative C Negative Negative Positive - 1 mole of $H_2$ and 2 moles of $I_2$ are taken initially in a 2 litre vessel. The number of moles of $H_2$ at equilibrium is 0.2. Then the number of moles of $I_2$ and HI at equilibrium is
- The pH of a buffer containing equal molarconcentration of a weak base and its chloride ( $K_b$ for weak base = $2 \times 10^{-5}$, log 2 = 0.3) is
- Atomic radius (pm) of Al, Si, N and F respectively is
- Consider the following electrode process of a cell, $ {Cl^{-1} -> \frac{1}{2} Cl_2 + e^{-}}$ $ {[MCl + e^{-} -> M + Cl^{-} ] }$ If EMF of this cell is $-1.140\, V$ and $E^0$ value of the cell is $-0.55\,V$ at $298\,K$, the value of the equilibrium constant of the sparingly soluble salt MCl is in the order of
View More Questions
Top TS EAMCET p -Block Elements Questions
- Producer gas is a mixture of
- \Mien borax is heated dining borax bead test along with CoO (Cobalt Oxide) on a loop of platinum (Pt) wire, it swells up and produces a blue colored bead. Which of the following compounds is responsible for the blue color?
Which of the following can form iconic micelles in water?
The ore which is purified by leaching process is:
XeF4 + O2F2 ā X + O2
X + H2O ā Y +2HF
The shape of the molecules of X and Y respectively are:
View More Questions
Top TS EAMCET Questions
- A bag contains $5$ red balls, $3$ black balls and $4$ white balls are drawn at random. The probability that they are not of same colour is
- If $cosec\, \theta - \cot \theta = 2017$, then quadrant in which $\theta $ lies is
- If $a$ is a unit vector, then $| a \times \hat{ i }|^{2}+| a \times \hat{ j }|^{2}+| a \times \hat{ k }|^{2}=$
- $A$ straight line makes an intercept on the $Y$-axis twice as long as that on $X$-axis and is at a unit distance from the origin. Then the line is represented by the equations
- Let $S$ and $S'$ be the foci of an ellipse and B be one end of its minor axis. If $SBS'$ is an isosceles right angled triangle then the eccentricity of the ellipse is
View More Questions