Question

Consider the following lonization steps
$M\left(g\right)\to M^{+}\left(g\right)+e-;\Delta H=100eV$
$M\left(g\right)\to M^{2+}\left(g\right)+e-;\Delta H=250eV$ select correct statements (s)

• A. $I.E{.}_1$ of M(g) is 100 eV
• B. $I.E{.}_1$ of $M^{+}$ (g) is 150 eV
• C. $I.E{.}_2$ of M(g) is 250 eV
• D. $I.E{.}_2$ of M(g) is 150 eV

Answer 1

Answer: (A), (B), (C)

The correct options are
A $I.E{.}_1$ of M(g) is 100 eV
B $I.E{.}_2$ of M(g) is 250 eV
C $I.E{.}_1$ of $M^{+}$ (g) is 150 eV

First Ionization Energy:
First ionization energy of an atom is the energy required to remove the first electron from the outermost shell of an atom. Once the first electron has been removed from the gaseous atom, it is possible to remove second and successive electrons from positive ions one after the other.
Second Ionization Energy:

Once the first ionization electron is removed from the gaseous atom, it is possible to remove second and successive electrons from positive ions one after the other. Removal of a second electron from an already ionized gaseous atom is called as second ionization energy.

$A\left(g\right)+I{E}_1\to A^{+}\left(g\right)+e^{-}$ [First Ionization]
$A^{+}\left(g\right)+I{E}_1{A}^{2+}\left(g\right)+e^{-}$ [Second ionization]

The amount of energies required to remove most loosely bound electron from unipositive, dipositive, tripositive .... ions of the element in gaseous state are called second, third, fourth, etc ionization energies respectively.
The second, third and fourth, etc ionization energies are collectively called as successive ionization energies.
It is also seen that IE3 > IE2 > IE1.
So options A, B & C are correct.