How would you distinguish between the first, second, and third ionization energies of an atom?

1 Answer
Oct 27, 2015

The first ionization energy is the energy it takes to remove an electron from a neutral atom.
The second ionization energy is the energy it takes to remove an electron from a 1+ ion. (That means that the atom has already lost one electron, you are now removing the second.)
The third ionization energy is the energy it takes to remove an electron from a 2+ ion. (That means that the atom has already lost two electrons, you are now removing the third.)

And 2nd ionization energy is higher than 1st ionization energy, 3rd is higher than 2nd, and so forth.

(I just wanted to clarify from an above answer: 2nd i.e. is not the energy it takes to remove 2 electrons together; it's the energy it takes to remove 1 electron from an atom that has already lost 1 electron before.)