Question

What is the ionization potential of an atom?

Answer 1

Hint: From the word ionization itself one can come to know that it is the process of forming an ion. Ion is an atom in which the number of protons is greater than the number of electrons. That means the net charge on an atom is positive called a cation.

Complete solution:
An atom consists of protons, neutrons and electrons. The protons and the neutrons are present inside the nucleus whereas the electrons orbit in a circular shaped path depending on the different energy levels of that particular atom.
The electrons in an orbit of an atom can only have a certain definite value of energy while revolving indifferent orbits. This is called energy quantization
The energy permitted for an electron in an atom of atomic no denoted by Z is given by,
${{E}_{n}}=\dfrac{2{{\pi }^{2}}m{{k}^{2}}{{Z}^{2}}{{e}^{4}}}{{{n}^{2}}{{h}^{2}}}J$
In the above equation,
 m is the mass of electron,
k is the permittivity of free space,
e is the charge of an electron ,
n is the energy level in the atom,
h is the planck's constant.
The energy state i.e. n=1 is called the ground state has the lowest energy .
Hence we are ready to define Ionization potential
Ionization potential is that accelerating potential which gives a bombarding electron sufficient energy to ionize the target atom by removing one of the electrons out of the atom.
Mathematically from the above equation,
It means removing an electron from n equal to say some n to $n=\infty $.

Note:
As mentioned earlier ionization means, removing an electron from an isolated gaseous atom. But there are other terms like ionization enthalpy or some similar terms which have a different meaning. Otherwise all the terms have similar meaning with suffix ionization.