Question

if the ionization potential of Li+2 is 122.4ev. find out 6th IP of carbon

Answer 1

Answer: 6th ionization potential for carbon atom is -489.6eV

Explanation: Ionization energy is defined as the measure of energy from (+1) ground energy level to (infinity) energy level.

Mathematically,

$I.E.=E_{\infty }-E_1$

Energy associated to the $n^{th}$ - energy level will be:

$E_n=\frac{E_o\times Z^2}{n^2}$    .....(1)

For ground state energy level of $Li^{2+}-ion$, n = 1 and Z = 3

Ionization energy = 122.4 eV (given)

Putting the values in equation 1, we get

$122.4eV=0-\frac{E_o\times 3^2}{1^2}$

$E_o=-13.6eV$

Now, to calculate the sixth ionization potential for carbon, we must know the principle quantum number for this atom. So to know that

Atomic number of Carbon = 6

And we are asked to find the 6th ionization potential which means that 5 electrons are already released and the electronic configuration for $C^{5+}$ is $1s^2$

So, the principle quantum number for the 6th ionization step = 1

Putting the values in equation 1, we get

$E_1=\frac{-13.6eV\times (6)^2}{(1)^2}=-489.6eV$

$E_1=-489.6eV$