Enter the energy of the system with an electron and the energy of the anion into the Electron Affinity Calculator. The calculator will evaluate the Electron Affinity. 

Electron Affinity Formula

The following two example problems outline the steps and information needed to calculate the Electron Affinity.

EA = Ee - Ea

Variables:

  • EA is the Electron Affinity ( )
  • Ee is the energy of the system with an electron 
  • Ea is the energy of the anion 

To calculate the electron affinity, subtract the energy of the anion from the energy of the system.

How to Calculate Electron Affinity?

The following steps outline how to calculate the Electron Affinity.


  1. First, determine the energy of the system with an electron. 
  2. Next, determine the energy of the anion. 
  3. Next, gather the formula from above = EA = Ee – Ea.
  4. Finally, calculate the Electron Affinity.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

energy of the system with an electron = 5

energy of the anion = 3

EA = Ee – Ea = ?