Ionization Energy Formula
Thus the ionization energy is the energy difference between the energy of the electron in the initial orbit and the energy of the electron outside the atom (infinite orbit in this case).
According to Bohr, the energy of an electron in the nth orbit is given by:
where,
m is mass of one electron,
e is charge on one electron,
h is Planck’s constant,
Z is atomic number,
n is the orbit from which electron is removedThis formula can be rewritten as,
En =−R × n2 / Z2
En = −13.6 × n2 / Z2 eV / atom
This is the energy of the atom in the nth orbit. Now we said that the ionization energy is the energy difference between the energy of the electron in the initial orbit and the energy of the electron in the infinite orbit. Thus we can consider the initial orbit as n1 = n and the final orbit as n2 = ∞.
IE = En2 − En1 = ΔE
As
This formula is known as the ionization energy formula. Note that the IE is the same as the energy of the electron in the nth orbit but positive in sign. This is due to the fact that the energy is supplied to remove the electron and thus it has a positive sign.
Ionization Energy
Ionization energy can be defined as the minimum amount of energy required to remove the valence electron i.e. the most loosely bound electron from an isolated gaseous atom or ion. It is important to note the term isolated gaseous atom as if the atom is not isolated, then the energy required may be more due to the interatomic forces.
Let’s learn about Ionization Energy in detail in this article.