Without electrons atoms would carry what charge?
Why, a positive charge, i.e. an opposite charge to the electronic charge.
Protons, fundamental, massive nuclear particles are conceived to have an opposite electronic charge to electrons, fundamental particles of negligible mass that are conceived to whizz about the nuclear charge, and the nucleus.
Should an electron be removed, the atom would become a positively charged ion:
And we can measure the energetics of the reaction..........