First, let's understand the concept of ionization potential:
The ionization potential of an atom is the minimum amount of energy required to remove an electron from the outermost shell of an atom and make it a positively charged ion. It is typically measured in electron volts (eV).

What is the first exciting potential?
The first exciting potential, also known as the first ionization energy, is the energy required to remove the first electron from an atom when it is in its ground state and make it a positively charged ion. It represents the energy level at which an electron transitions from the ground state to the first excited state.

Calculating the first exciting potential:
To calculate the first exciting potential, we need to consider the ionization potential of the atom. The first exciting potential will be equal to the ionization potential plus the energy of the ground state.

Formula:
First Exciting Potential = Ionization Potential + Energy of Ground State

Explanation:
The ionization potential of the atom is given as 20V. This represents the energy required to remove an electron from the outermost shell. The first exciting potential will be higher than the ionization potential because it includes the energy of the ground state.

The energy of the ground state is the energy level at which the atom is in its lowest energy configuration. It is typically represented by the principal quantum number (n=1). The energy level of the ground state is considered to be zero.

Therefore, to calculate the first exciting potential, we add the ionization potential (20V) to the energy of the ground state (0V).

First Exciting Potential = 20V + 0V = 20V

Hence, the first exciting potential of the atom will also be 20V. This means that to transition from the ground state to the first excited state, an additional energy of 20V is required.