The radius of La3+ (Atomic number of La = 57 ) is 1.06 mathringA. Which one of the following given values will be closest to the radius of Lu3+ (Atomic number of Lu = 71) ?

Question

The radius of La3+ (Atomic number of La = 57 ) is 1.06 mathringA. Which one of the following given values will be closest to the radius of Lu3+ (Atomic number of Lu = 71) ? (A) 1.40 mathringA (B) 1.06 mathringA (C) 0.85 mathringA (D) 1.60 mathringA

Tardigrade Admin · Accepted Answer

Ionic radii propto (1/z) Thus, (z2/z1) ⇒ (1.06/( textIonic radii of Lu3+)) = (71/57) ⇒ Ionic radii of Lu3+ = 0.85 mathringA

Q. The radius of $L a^{3 +}$ (Atomic number of $L a = 57$ ) is $1.06 \overset{˚}{A}$ . Which one of the following given values will be closest to the radius of $L u^{3 +}$ (Atomic number of $Lu = 71$ ) ?

$1.40 \overset{˚}{A}$

$1.06 \overset{˚}{A}$

$0.85 \overset{˚}{A}$

$1.60 \overset{˚}{A}$

Ionic radii $\propto \frac{1}{z}$
Thus, $\frac{z _{2}}{z _{1}} \Rightarrow \frac{1.06}{( Ionic radii of L u ^{3 +} )} = \frac{71}{57}$
$\Rightarrow$ Ionic radii of $L u^{3 +} = 0.85 \overset{˚}{A}$

Q. The radius of La3+ (Atomic number of La=57 ) is 1.06A˚. Which one of the following given values will be closest to the radius of Lu3+ (Atomic number of Lu=71) ?

1.40A˚

1.06A˚

0.85A˚

1.60A˚