Dimensional formula for work done is

The second ionization enthalpy refers to the energy required to remove a second electron from a positively charged ion. It is expressed in terms of energy per unit (e.g., joules or erg), which simplifies to:

[M⁰L²T^-2]

Explanation:

• [M¹L²T^-2]: Represents force, not ionization energy.
• [M⁰L⁰T^-2]: Incorrect, as ionization energy must include a length term due to its work definition.
• [M²L²T^-2]: Incorrect, as this suggests a squared mass term, which is unrelated.
• [M⁰L²T^-2]: Correct, as ionization energy is defined as work done (force × distance), giving the dimension of energy.