MCQ
Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason$(R):$

Assertion $(A):$ The ionic radii of $O ^{2-}$ and $Mg ^{2+}$ are same.

Reason $( R )$ : Both $O ^{2-}$ and $Mg ^{2+}$ are isoelectronic species.

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

  • A
    Both $(A)$ and $(R)$ are true and $(R)$ is the correct explanation of $( A )$
  • B
    Both $(A)$ and $(R)$ are true but $(R)$ is not the correct explanation of $(A)$
  • C
    $(A)$ is true but $(R)$ is false
  • $(A)$ is false but $(R)$ is true

Answer

Correct option: D.
$(A)$ is false but $(R)$ is true
d
Ionic radius of $O ^{2-}$ is more than that of $Mg ^{2+}$

Both $O ^{2-}$ and $Mg ^{2+}$ are isoelectronic with $10$ electrons

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

An ideal gas undergoes a cyclic process as shown in Figure

$\Delta {U_{BC}} =  - 5\,kJ\,mo{l^{ - 1}},{q_{AB}} = 2\,kJ\,mo{l^{ - 1}}$

$\Delta {W_{AB}} =  - 5\,kJ\,mo{l^{ - 1}},{W_{CA}} = 3\,kJ\,mo{l^{ - 1}}$ 

Heat absorbed by the system during process $CA$ is......$kJ\,mo{l^{ - 1}}$

Which of the following depict the same ?
Which molecule is linear
If the wavelength for an electron emitted from $H$ atom is $3.3 \times 10^{-10}\,m$, then energy absorbed by the electron in its ground state compared to minimum energy required for its escape from the atom, is $.......$times. (Nearest integer).

[Given $: h =6.626 \times 10^{-34}\,Js$,Mass of electron $=9.1 \times 10^{-31}$ ]

Isotopes have same____but different____.
$Be's$ $4^{th}$ electron will have four quantum numbers

            $n$                  $l$                 $m$                 $s$

Carbon and carbon monoxide burn in oxygen to form carbon dioxide according to the following reactions

$C + {O_2} \to C{O_2};\,\Delta H = - 394\,kJ\,mo{l^{ - 1}}$

$2CO + {O_2} \to 2C{O_2};\,\Delta H = - 569\,kJ\,mo{l^{ - 1}}$ The heat of formation of $1\,mol$ of carbon monoxide is thus .....$kJ\,mo{l^{ - 1}}$

The atomic number of Uut is:
If a rocket runs on a fuel $\left( C _{15} H _{30}\right)$ and liquid oxygen, the weight of oxygen required and $CO _{2}$ released for every litre of fuel respectively are: (Given: density of the fuel is $0.756\, g / mL$ )
The overall complex dissociation equilibrium constant for the complex $[Cu(NH_3)_4]^{2+}$ ion will be ( $\beta _4$ for this complex is $2.1\times 10^{13}$ ) $\beta _4 =$ association constant